src/common/datetime.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/datetime.cpp
   3 // Purpose:     implementation of time/date related classes
   4 //              (for formatting&parsing see datetimefmt.cpp)
   5 // Author:      Vadim Zeitlin
   6 // Modified by:
   7 // Created:     11.05.99
   8 // Copyright:   (c) 1999 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 //              parts of code taken from sndcal library by Scott E. Lee:
  10 //
  11 //               Copyright 1993-1995, Scott E. Lee, all rights reserved.
  12 //               Permission granted to use, copy, modify, distribute and sell
  13 //               so long as the above copyright and this permission statement
  14 //               are retained in all copies.
  15 //
  16 // Licence:     wxWindows licence
  17 ///////////////////////////////////////////////////////////////////////////////
  18
  19 /*
  20  * Implementation notes:
  21  *
  22  * 1. the time is stored as a 64bit integer containing the signed number of
  23  *    milliseconds since Jan 1. 1970 (the Unix Epoch) - so it is always
  24  *    expressed in GMT.
  25  *
  26  * 2. the range is thus something about 580 million years, but due to current
  27  *    algorithms limitations, only dates from Nov 24, 4714BC are handled
  28  *
  29  * 3. standard ANSI C functions are used to do time calculations whenever
  30  *    possible, i.e. when the date is in the range Jan 1, 1970 to 2038
  31  *
  32  * 4. otherwise, the calculations are done by converting the date to/from JDN
  33  *    first (the range limitation mentioned above comes from here: the
  34  *    algorithm used by Scott E. Lee's code only works for positive JDNs, more
  35  *    or less)
  36  *
  37  * 5. the object constructed for the given DD-MM-YYYY HH:MM:SS corresponds to
  38  *    this moment in local time and may be converted to the object
  39  *    corresponding to the same date/time in another time zone by using
  40  *    ToTimezone()
  41  *
  42  * 6. the conversions to the current (or any other) timezone are done when the
  43  *    internal time representation is converted to the broken-down one in
  44  *    wxDateTime::Tm.
  45  */
  46
  47 // ============================================================================
  48 // declarations
  49 // ============================================================================
  50
  51 // ----------------------------------------------------------------------------
  52 // headers
  53 // ----------------------------------------------------------------------------
  54
  55 // For compilers that support precompilation, includes "wx.h".
  56 #include "wx/wxprec.h"
  57
  58 #ifdef __BORLANDC__
  59     #pragma hdrstop
  60 #endif
  61
  62 #if !defined(wxUSE_DATETIME) || wxUSE_DATETIME
  63
  64 #ifndef WX_PRECOMP
  65     #ifdef __WINDOWS__
  66         #include "wx/msw/wrapwin.h"
  67     #endif
  68     #include "wx/string.h"
  69     #include "wx/log.h"
  70     #include "wx/intl.h"
  71     #include "wx/stopwatch.h"           // for wxGetLocalTimeMillis()
  72     #include "wx/module.h"
  73     #include "wx/crt.h"
  74 #endif // WX_PRECOMP
  75
  76 #include "wx/thread.h"
  77 #include "wx/time.h"
  78 #include "wx/tokenzr.h"
  79
  80 #include <ctype.h>
  81
  82 #ifdef __WINDOWS__
  83     #include <winnls.h>
  84     #ifndef __WXWINCE__
  85         #include <locale.h>
  86     #endif
  87 #endif
  88
  89 #include "wx/datetime.h"
  90
  91 // ----------------------------------------------------------------------------
  92 // wxXTI
  93 // ----------------------------------------------------------------------------
  94
  95 #if wxUSE_EXTENDED_RTTI
  96
  97 template<> void wxStringReadValue(const wxString &s , wxDateTime &data )
  98 {
  99     data.ParseFormat(s,"%Y-%m-%d %H:%M:%S", NULL);
 100 }
 101
 102 template<> void wxStringWriteValue(wxString &s , const wxDateTime &data )
 103 {
 104     s = data.Format("%Y-%m-%d %H:%M:%S");
 105 }
 106
 107 wxCUSTOM_TYPE_INFO(wxDateTime, wxToStringConverter<wxDateTime> , wxFromStringConverter<wxDateTime>)
 108
 109 #endif // wxUSE_EXTENDED_RTTI
 110
 111 // ----------------------------------------------------------------------------
 112 // macros
 113 // ----------------------------------------------------------------------------
 114
 115 // debugging helper: just a convenient replacement of wxCHECK()
 116 #define wxDATETIME_CHECK(expr, msg) \
 117     wxCHECK2_MSG(expr, *this = wxInvalidDateTime; return *this, msg)
 118
 119 // ----------------------------------------------------------------------------
 120 // private classes
 121 // ----------------------------------------------------------------------------
 122
 123 class wxDateTimeHolidaysModule : public wxModule
 124 {
 125 public:
 126     virtual bool OnInit()
 127     {
 128         wxDateTimeHolidayAuthority::AddAuthority(new wxDateTimeWorkDays);
 129
 130         return true;
 131     }
 132
 133     virtual void OnExit()
 134     {
 135         wxDateTimeHolidayAuthority::ClearAllAuthorities();
 136         wxDateTimeHolidayAuthority::ms_authorities.clear();
 137     }
 138
 139 private:
 140     DECLARE_DYNAMIC_CLASS(wxDateTimeHolidaysModule)
 141 };
 142
 143 IMPLEMENT_DYNAMIC_CLASS(wxDateTimeHolidaysModule, wxModule)
 144
 145 // ----------------------------------------------------------------------------
 146 // constants
 147 // ----------------------------------------------------------------------------
 148
 149 // some trivial ones
 150 static const int MONTHS_IN_YEAR = 12;
 151
 152 static const int SEC_PER_MIN = 60;
 153
 154 static const int MIN_PER_HOUR = 60;
 155
 156 static const long SECONDS_PER_DAY = 86400l;
 157
 158 static const int DAYS_PER_WEEK = 7;
 159
 160 static const long MILLISECONDS_PER_DAY = 86400000l;
 161
 162 // this is the integral part of JDN of the midnight of Jan 1, 1970
 163 // (i.e. JDN(Jan 1, 1970) = 2440587.5)
 164 static const long EPOCH_JDN = 2440587l;
 165
 166 // these values are only used in asserts so don't define them if asserts are
 167 // disabled to avoid warnings about unused static variables
 168 #if wxDEBUG_LEVEL
 169 // the date of JDN -0.5 (as we don't work with fractional parts, this is the
 170 // reference date for us) is Nov 24, 4714BC
 171 static const int JDN_0_YEAR = -4713;
 172 static const int JDN_0_MONTH = wxDateTime::Nov;
 173 static const int JDN_0_DAY = 24;
 174 #endif // wxDEBUG_LEVEL
 175
 176 // the constants used for JDN calculations
 177 static const long JDN_OFFSET         = 32046l;
 178 static const long DAYS_PER_5_MONTHS  = 153l;
 179 static const long DAYS_PER_4_YEARS   = 1461l;
 180 static const long DAYS_PER_400_YEARS = 146097l;
 181
 182 // this array contains the cumulated number of days in all previous months for
 183 // normal and leap years
 184 static const wxDateTime::wxDateTime_t gs_cumulatedDays[2][MONTHS_IN_YEAR] =
 185 {
 186     { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
 187     { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 }
 188 };
 189
 190 const long wxDateTime::TIME_T_FACTOR = 1000l;
 191
 192 // ----------------------------------------------------------------------------
 193 // global data
 194 // ----------------------------------------------------------------------------
 195
 196 const char wxDefaultDateTimeFormat[] = "%c";
 197 const char wxDefaultTimeSpanFormat[] = "%H:%M:%S";
 198
 199 // in the fine tradition of ANSI C we use our equivalent of (time_t)-1 to
 200 // indicate an invalid wxDateTime object
 201 const wxDateTime wxDefaultDateTime;
 202
 203 wxDateTime::Country wxDateTime::ms_country = wxDateTime::Country_Unknown;
 204
 205 // ----------------------------------------------------------------------------
 206 // private functions
 207 // ----------------------------------------------------------------------------
 208
 209 // debugger helper: this function can be called from a debugger to show what
 210 // the date really is
 211 extern const char *wxDumpDate(const wxDateTime* dt)
 212 {
 213     static char buf[128];
 214
 215     wxString fmt(dt->Format("%Y-%m-%d (%a) %H:%M:%S"));
 216     wxStrlcpy(buf,
 217               (fmt + " (" + dt->GetValue().ToString() + " ticks)").ToAscii(),
 218               WXSIZEOF(buf));
 219
 220     return buf;
 221 }
 222
 223 // get the number of days in the given month of the given year
 224 static inline
 225 wxDateTime::wxDateTime_t GetNumOfDaysInMonth(int year, wxDateTime::Month month)
 226 {
 227     // the number of days in month in Julian/Gregorian calendar: the first line
 228     // is for normal years, the second one is for the leap ones
 229     static const wxDateTime::wxDateTime_t daysInMonth[2][MONTHS_IN_YEAR] =
 230     {
 231         { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 232         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 233     };
 234
 235     return daysInMonth[wxDateTime::IsLeapYear(year)][month];
 236 }
 237
 238 // return the integral part of the JDN for the midnight of the given date (to
 239 // get the real JDN you need to add 0.5, this is, in fact, JDN of the
 240 // noon of the previous day)
 241 static long GetTruncatedJDN(wxDateTime::wxDateTime_t day,
 242                             wxDateTime::Month mon,
 243                             int year)
 244 {
 245     // CREDIT: code below is by Scott E. Lee (but bugs are mine)
 246
 247     // check the date validity
 248     wxASSERT_MSG(
 249       (year > JDN_0_YEAR) ||
 250       ((year == JDN_0_YEAR) && (mon > JDN_0_MONTH)) ||
 251       ((year == JDN_0_YEAR) && (mon == JDN_0_MONTH) && (day >= JDN_0_DAY)),
 252       wxT("date out of range - can't convert to JDN")
 253                 );
 254
 255     // make the year positive to avoid problems with negative numbers division
 256     year += 4800;
 257
 258     // months are counted from March here
 259     int month;
 260     if ( mon >= wxDateTime::Mar )
 261     {
 262         month = mon - 2;
 263     }
 264     else
 265     {
 266         month = mon + 10;
 267         year--;
 268     }
 269
 270     // now we can simply add all the contributions together
 271     return ((year / 100) * DAYS_PER_400_YEARS) / 4
 272             + ((year % 100) * DAYS_PER_4_YEARS) / 4
 273             + (month * DAYS_PER_5_MONTHS + 2) / 5
 274             + day
 275             - JDN_OFFSET;
 276 }
 277
 278 #ifdef wxHAS_STRFTIME
 279
 280 // this function is a wrapper around strftime(3) adding error checking
 281 // NOTE: not static because used by datetimefmt.cpp
 282 wxString CallStrftime(const wxString& format, const tm* tm)
 283 {
 284     wxChar buf[4096];
 285     // Create temp wxString here to work around mingw/cygwin bug 1046059
 286     // http://sourceforge.net/tracker/?func=detail&atid=102435&aid=1046059&group_id=2435
 287     wxString s;
 288
 289     if ( !wxStrftime(buf, WXSIZEOF(buf), format, tm) )
 290     {
 291         // There is one special case in which strftime() can return 0 without
 292         // indicating an error: "%p" may give empty string depending on the
 293         // locale, so check for it explicitly. Apparently it's really the only
 294         // exception.
 295         if ( format != wxS("%p") )
 296         {
 297             // if the format is valid, buffer must be too small?
 298             wxFAIL_MSG(wxT("strftime() failed"));
 299         }
 300
 301         buf[0] = '\0';
 302     }
 303
 304     s = buf;
 305     return s;
 306 }
 307
 308 #endif // wxHAS_STRFTIME
 309
 310 // if year and/or month have invalid values, replace them with the current ones
 311 static void ReplaceDefaultYearMonthWithCurrent(int *year,
 312                                                wxDateTime::Month *month)
 313 {
 314     struct tm *tmNow = NULL;
 315     struct tm tmstruct;
 316
 317     if ( *year == wxDateTime::Inv_Year )
 318     {
 319         tmNow = wxDateTime::GetTmNow(&tmstruct);
 320
 321         *year = 1900 + tmNow->tm_year;
 322     }
 323
 324     if ( *month == wxDateTime::Inv_Month )
 325     {
 326         if ( !tmNow )
 327             tmNow = wxDateTime::GetTmNow(&tmstruct);
 328
 329         *month = (wxDateTime::Month)tmNow->tm_mon;
 330     }
 331 }
 332
 333 // fill the struct tm with default values
 334 // NOTE: not static because used by datetimefmt.cpp
 335 void InitTm(struct tm& tm)
 336 {
 337     // struct tm may have etxra fields (undocumented and with unportable
 338     // names) which, nevertheless, must be set to 0
 339     memset(&tm, 0, sizeof(struct tm));
 340
 341     tm.tm_mday = 1;   // mday 0 is invalid
 342     tm.tm_year = 76;  // any valid year
 343     tm.tm_isdst = -1; // auto determine
 344 }
 345
 346 // ============================================================================
 347 // implementation of wxDateTime
 348 // ============================================================================
 349
 350 // ----------------------------------------------------------------------------
 351 // struct Tm
 352 // ----------------------------------------------------------------------------
 353
 354 wxDateTime::Tm::Tm()
 355 {
 356     year = (wxDateTime_t)wxDateTime::Inv_Year;
 357     mon = wxDateTime::Inv_Month;
 358     mday =
 359     yday = 0;
 360     hour =
 361     min =
 362     sec =
 363     msec = 0;
 364     wday = wxDateTime::Inv_WeekDay;
 365 }
 366
 367 wxDateTime::Tm::Tm(const struct tm& tm, const TimeZone& tz)
 368               : m_tz(tz)
 369 {
 370     msec = 0;
 371     sec = (wxDateTime::wxDateTime_t)tm.tm_sec;
 372     min = (wxDateTime::wxDateTime_t)tm.tm_min;
 373     hour = (wxDateTime::wxDateTime_t)tm.tm_hour;
 374     mday = (wxDateTime::wxDateTime_t)tm.tm_mday;
 375     mon = (wxDateTime::Month)tm.tm_mon;
 376     year = 1900 + tm.tm_year;
 377     wday = (wxDateTime::wxDateTime_t)tm.tm_wday;
 378     yday = (wxDateTime::wxDateTime_t)tm.tm_yday;
 379 }
 380
 381 bool wxDateTime::Tm::IsValid() const
 382 {
 383     if ( mon == wxDateTime::Inv_Month )
 384         return false;
 385
 386     // We need to check this here to avoid crashing in GetNumOfDaysInMonth() if
 387     // somebody passed us "(wxDateTime::Month)1000".
 388     wxCHECK_MSG( mon >= wxDateTime::Jan && mon < wxDateTime::Inv_Month, false,
 389                  wxS("Invalid month value") );
 390
 391     // we allow for the leap seconds, although we don't use them (yet)
 392     return (year != wxDateTime::Inv_Year) && (mon != wxDateTime::Inv_Month) &&
 393            (mday > 0 && mday <= GetNumOfDaysInMonth(year, mon)) &&
 394            (hour < 24) && (min < 60) && (sec < 62) && (msec < 1000);
 395 }
 396
 397 void wxDateTime::Tm::ComputeWeekDay()
 398 {
 399     // compute the week day from day/month/year: we use the dumbest algorithm
 400     // possible: just compute our JDN and then use the (simple to derive)
 401     // formula: weekday = (JDN + 1.5) % 7
 402     wday = (wxDateTime::wxDateTime_t)((GetTruncatedJDN(mday, mon, year) + 2) % 7);
 403 }
 404
 405 void wxDateTime::Tm::AddMonths(int monDiff)
 406 {
 407     // normalize the months field
 408     while ( monDiff < -mon )
 409     {
 410         year--;
 411
 412         monDiff += MONTHS_IN_YEAR;
 413     }
 414
 415     while ( monDiff + mon >= MONTHS_IN_YEAR )
 416     {
 417         year++;
 418
 419         monDiff -= MONTHS_IN_YEAR;
 420     }
 421
 422     mon = (wxDateTime::Month)(mon + monDiff);
 423
 424     wxASSERT_MSG( mon >= 0 && mon < MONTHS_IN_YEAR, wxT("logic error") );
 425
 426     // NB: we don't check here that the resulting date is valid, this function
 427     //     is private and the caller must check it if needed
 428 }
 429
 430 void wxDateTime::Tm::AddDays(int dayDiff)
 431 {
 432     // normalize the days field
 433     while ( dayDiff + mday < 1 )
 434     {
 435         AddMonths(-1);
 436
 437         dayDiff += GetNumOfDaysInMonth(year, mon);
 438     }
 439
 440     mday = (wxDateTime::wxDateTime_t)( mday + dayDiff );
 441     while ( mday > GetNumOfDaysInMonth(year, mon) )
 442     {
 443         mday -= GetNumOfDaysInMonth(year, mon);
 444
 445         AddMonths(1);
 446     }
 447
 448     wxASSERT_MSG( mday > 0 && mday <= GetNumOfDaysInMonth(year, mon),
 449                   wxT("logic error") );
 450 }
 451
 452 // ----------------------------------------------------------------------------
 453 // class TimeZone
 454 // ----------------------------------------------------------------------------
 455
 456 wxDateTime::TimeZone::TimeZone(wxDateTime::TZ tz)
 457 {
 458     switch ( tz )
 459     {
 460         case wxDateTime::Local:
 461             // get the offset from C RTL: it returns the difference GMT-local
 462             // while we want to have the offset _from_ GMT, hence the '-'
 463             m_offset = -wxGetTimeZone();
 464             break;
 465
 466         case wxDateTime::GMT_12:
 467         case wxDateTime::GMT_11:
 468         case wxDateTime::GMT_10:
 469         case wxDateTime::GMT_9:
 470         case wxDateTime::GMT_8:
 471         case wxDateTime::GMT_7:
 472         case wxDateTime::GMT_6:
 473         case wxDateTime::GMT_5:
 474         case wxDateTime::GMT_4:
 475         case wxDateTime::GMT_3:
 476         case wxDateTime::GMT_2:
 477         case wxDateTime::GMT_1:
 478             m_offset = -3600*(wxDateTime::GMT0 - tz);
 479             break;
 480
 481         case wxDateTime::GMT0:
 482         case wxDateTime::GMT1:
 483         case wxDateTime::GMT2:
 484         case wxDateTime::GMT3:
 485         case wxDateTime::GMT4:
 486         case wxDateTime::GMT5:
 487         case wxDateTime::GMT6:
 488         case wxDateTime::GMT7:
 489         case wxDateTime::GMT8:
 490         case wxDateTime::GMT9:
 491         case wxDateTime::GMT10:
 492         case wxDateTime::GMT11:
 493         case wxDateTime::GMT12:
 494         case wxDateTime::GMT13:
 495             m_offset = 3600*(tz - wxDateTime::GMT0);
 496             break;
 497
 498         case wxDateTime::A_CST:
 499             // Central Standard Time in use in Australia = UTC + 9.5
 500             m_offset = 60l*(9*MIN_PER_HOUR + MIN_PER_HOUR/2);
 501             break;
 502
 503         default:
 504             wxFAIL_MSG( wxT("unknown time zone") );
 505     }
 506 }
 507
 508 // ----------------------------------------------------------------------------
 509 // static functions
 510 // ----------------------------------------------------------------------------
 511
 512 /* static */
 513 struct tm *wxDateTime::GetTmNow(struct tm *tmstruct)
 514 {
 515     time_t t = GetTimeNow();
 516     return wxLocaltime_r(&t, tmstruct);
 517 }
 518
 519 /* static */
 520 bool wxDateTime::IsLeapYear(int year, wxDateTime::Calendar cal)
 521 {
 522     if ( year == Inv_Year )
 523         year = GetCurrentYear();
 524
 525     if ( cal == Gregorian )
 526     {
 527         // in Gregorian calendar leap years are those divisible by 4 except
 528         // those divisible by 100 unless they're also divisible by 400
 529         // (in some countries, like Russia and Greece, additional corrections
 530         // exist, but they won't manifest themselves until 2700)
 531         return (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0));
 532     }
 533     else if ( cal == Julian )
 534     {
 535         // in Julian calendar the rule is simpler
 536         return year % 4 == 0;
 537     }
 538     else
 539     {
 540         wxFAIL_MSG(wxT("unknown calendar"));
 541
 542         return false;
 543     }
 544 }
 545
 546 /* static */
 547 int wxDateTime::GetCentury(int year)
 548 {
 549     return year > 0 ? year / 100 : year / 100 - 1;
 550 }
 551
 552 /* static */
 553 int wxDateTime::ConvertYearToBC(int year)
 554 {
 555     // year 0 is BC 1
 556     return year > 0 ? year : year - 1;
 557 }
 558
 559 /* static */
 560 int wxDateTime::GetCurrentYear(wxDateTime::Calendar cal)
 561 {
 562     switch ( cal )
 563     {
 564         case Gregorian:
 565             return Now().GetYear();
 566
 567         case Julian:
 568             wxFAIL_MSG(wxT("TODO"));
 569             break;
 570
 571         default:
 572             wxFAIL_MSG(wxT("unsupported calendar"));
 573             break;
 574     }
 575
 576     return Inv_Year;
 577 }
 578
 579 /* static */
 580 wxDateTime::Month wxDateTime::GetCurrentMonth(wxDateTime::Calendar cal)
 581 {
 582     switch ( cal )
 583     {
 584         case Gregorian:
 585             return Now().GetMonth();
 586
 587         case Julian:
 588             wxFAIL_MSG(wxT("TODO"));
 589             break;
 590
 591         default:
 592             wxFAIL_MSG(wxT("unsupported calendar"));
 593             break;
 594     }
 595
 596     return Inv_Month;
 597 }
 598
 599 /* static */
 600 wxDateTime::wxDateTime_t wxDateTime::GetNumberOfDays(int year, Calendar cal)
 601 {
 602     if ( year == Inv_Year )
 603     {
 604         // take the current year if none given
 605         year = GetCurrentYear();
 606     }
 607
 608     switch ( cal )
 609     {
 610         case Gregorian:
 611         case Julian:
 612             return IsLeapYear(year) ? 366 : 365;
 613
 614         default:
 615             wxFAIL_MSG(wxT("unsupported calendar"));
 616             break;
 617     }
 618
 619     return 0;
 620 }
 621
 622 /* static */
 623 wxDateTime::wxDateTime_t wxDateTime::GetNumberOfDays(wxDateTime::Month month,
 624                                                      int year,
 625                                                      wxDateTime::Calendar cal)
 626 {
 627     wxCHECK_MSG( month < MONTHS_IN_YEAR, 0, wxT("invalid month") );
 628
 629     if ( cal == Gregorian || cal == Julian )
 630     {
 631         if ( year == Inv_Year )
 632         {
 633             // take the current year if none given
 634             year = GetCurrentYear();
 635         }
 636
 637         return GetNumOfDaysInMonth(year, month);
 638     }
 639     else
 640     {
 641         wxFAIL_MSG(wxT("unsupported calendar"));
 642
 643         return 0;
 644     }
 645 }
 646
 647 namespace
 648 {
 649
 650 // helper function used by GetEnglish/WeekDayName(): returns 0 if flags is
 651 // Name_Full and 1 if it is Name_Abbr or -1 if the flags is incorrect (and
 652 // asserts in this case)
 653 //
 654 // the return value of this function is used as an index into 2D array
 655 // containing full names in its first row and abbreviated ones in the 2nd one
 656 int NameArrayIndexFromFlag(wxDateTime::NameFlags flags)
 657 {
 658     switch ( flags )
 659     {
 660         case wxDateTime::Name_Full:
 661             return 0;
 662
 663         case wxDateTime::Name_Abbr:
 664             return 1;
 665
 666         default:
 667             wxFAIL_MSG( "unknown wxDateTime::NameFlags value" );
 668     }
 669
 670     return -1;
 671 }
 672
 673 } // anonymous namespace
 674
 675 /* static */
 676 wxString wxDateTime::GetEnglishMonthName(Month month, NameFlags flags)
 677 {
 678     wxCHECK_MSG( month != Inv_Month, wxEmptyString, "invalid month" );
 679
 680     static const char *const monthNames[2][MONTHS_IN_YEAR] =
 681     {
 682         { "January", "February", "March", "April", "May", "June",
 683           "July", "August", "September", "October", "November", "December" },
 684         { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 685           "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }
 686     };
 687
 688     const int idx = NameArrayIndexFromFlag(flags);
 689     if ( idx == -1 )
 690         return wxString();
 691
 692     return monthNames[idx][month];
 693 }
 694
 695 /* static */
 696 wxString wxDateTime::GetMonthName(wxDateTime::Month month,
 697                                   wxDateTime::NameFlags flags)
 698 {
 699 #ifdef wxHAS_STRFTIME
 700     wxCHECK_MSG( month != Inv_Month, wxEmptyString, wxT("invalid month") );
 701
 702     // notice that we must set all the fields to avoid confusing libc (GNU one
 703     // gets confused to a crash if we don't do this)
 704     tm tm;
 705     InitTm(tm);
 706     tm.tm_mon = month;
 707
 708     return CallStrftime(flags == Name_Abbr ? wxT("%b") : wxT("%B"), &tm);
 709 #else // !wxHAS_STRFTIME
 710     return GetEnglishMonthName(month, flags);
 711 #endif // wxHAS_STRFTIME/!wxHAS_STRFTIME
 712 }
 713
 714 /* static */
 715 wxString wxDateTime::GetEnglishWeekDayName(WeekDay wday, NameFlags flags)
 716 {
 717     wxCHECK_MSG( wday != Inv_WeekDay, wxEmptyString, wxT("invalid weekday") );
 718
 719     static const char *const weekdayNames[2][DAYS_PER_WEEK] =
 720     {
 721         { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
 722           "Saturday" },
 723         { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" },
 724     };
 725
 726     const int idx = NameArrayIndexFromFlag(flags);
 727     if ( idx == -1 )
 728         return wxString();
 729
 730     return weekdayNames[idx][wday];
 731 }
 732
 733 /* static */
 734 wxString wxDateTime::GetWeekDayName(wxDateTime::WeekDay wday,
 735                                     wxDateTime::NameFlags flags)
 736 {
 737 #ifdef wxHAS_STRFTIME
 738     wxCHECK_MSG( wday != Inv_WeekDay, wxEmptyString, wxT("invalid weekday") );
 739
 740     // take some arbitrary Sunday (but notice that the day should be such that
 741     // after adding wday to it below we still have a valid date, e.g. don't
 742     // take 28 here!)
 743     tm tm;
 744     InitTm(tm);
 745     tm.tm_mday = 21;
 746     tm.tm_mon = Nov;
 747     tm.tm_year = 99;
 748
 749     // and offset it by the number of days needed to get the correct wday
 750     tm.tm_mday += wday;
 751
 752     // call mktime() to normalize it...
 753     (void)mktime(&tm);
 754
 755     // ... and call strftime()
 756     return CallStrftime(flags == Name_Abbr ? wxT("%a") : wxT("%A"), &tm);
 757 #else // !wxHAS_STRFTIME
 758     return GetEnglishWeekDayName(wday, flags);
 759 #endif // wxHAS_STRFTIME/!wxHAS_STRFTIME
 760 }
 761
 762 /* static */
 763 void wxDateTime::GetAmPmStrings(wxString *am, wxString *pm)
 764 {
 765     tm tm;
 766     InitTm(tm);
 767     wxChar buffer[64];
 768     // @Note: Do not call 'CallStrftime' here! CallStrftime checks the return code
 769     // and causes an assertion failed if the buffer is to small (which is good) - OR -
 770     // if strftime does not return anything because the format string is invalid - OR -
 771     // if there are no 'am' / 'pm' tokens defined for the current locale (which is not good).
 772     // wxDateTime::ParseTime will try several different formats to parse the time.
 773     // As a result, GetAmPmStrings might get called, even if the current locale
 774     // does not define any 'am' / 'pm' tokens. In this case, wxStrftime would
 775     // assert, even though it is a perfectly legal use.
 776     if ( am )
 777     {
 778         if (wxStrftime(buffer, WXSIZEOF(buffer), wxT("%p"), &tm) > 0)
 779             *am = wxString(buffer);
 780         else
 781             *am = wxString();
 782     }
 783     if ( pm )
 784     {
 785         tm.tm_hour = 13;
 786         if (wxStrftime(buffer, WXSIZEOF(buffer), wxT("%p"), &tm) > 0)
 787             *pm = wxString(buffer);
 788         else
 789             *pm = wxString();
 790     }
 791 }
 792
 793
 794 // ----------------------------------------------------------------------------
 795 // Country stuff: date calculations depend on the country (DST, work days,
 796 // ...), so we need to know which rules to follow.
 797 // ----------------------------------------------------------------------------
 798
 799 /* static */
 800 wxDateTime::Country wxDateTime::GetCountry()
 801 {
 802     // TODO use LOCALE_ICOUNTRY setting under Win32
 803 #ifndef __WXWINCE__
 804     if ( ms_country == Country_Unknown )
 805     {
 806         // try to guess from the time zone name
 807         time_t t = time(NULL);
 808         struct tm tmstruct;
 809         struct tm *tm = wxLocaltime_r(&t, &tmstruct);
 810
 811         wxString tz = CallStrftime(wxT("%Z"), tm);
 812         if ( tz == wxT("WET") || tz == wxT("WEST") )
 813         {
 814             ms_country = UK;
 815         }
 816         else if ( tz == wxT("CET") || tz == wxT("CEST") )
 817         {
 818             ms_country = Country_EEC;
 819         }
 820         else if ( tz == wxT("MSK") || tz == wxT("MSD") )
 821         {
 822             ms_country = Russia;
 823         }
 824         else if ( tz == wxT("AST") || tz == wxT("ADT") ||
 825                   tz == wxT("EST") || tz == wxT("EDT") ||
 826                   tz == wxT("CST") || tz == wxT("CDT") ||
 827                   tz == wxT("MST") || tz == wxT("MDT") ||
 828                   tz == wxT("PST") || tz == wxT("PDT") )
 829         {
 830             ms_country = USA;
 831         }
 832         else
 833         {
 834             // well, choose a default one
 835             ms_country = USA;
 836         }
 837     }
 838 #else // __WXWINCE__
 839      ms_country = USA;
 840 #endif // !__WXWINCE__/__WXWINCE__
 841
 842     return ms_country;
 843 }
 844
 845 /* static */
 846 void wxDateTime::SetCountry(wxDateTime::Country country)
 847 {
 848     ms_country = country;
 849 }
 850
 851 /* static */
 852 bool wxDateTime::IsWestEuropeanCountry(Country country)
 853 {
 854     if ( country == Country_Default )
 855     {
 856         country = GetCountry();
 857     }
 858
 859     return (Country_WesternEurope_Start <= country) &&
 860            (country <= Country_WesternEurope_End);
 861 }
 862
 863 // ----------------------------------------------------------------------------
 864 // DST calculations: we use 3 different rules for the West European countries,
 865 // USA and for the rest of the world. This is undoubtedly false for many
 866 // countries, but I lack the necessary info (and the time to gather it),
 867 // please add the other rules here!
 868 // ----------------------------------------------------------------------------
 869
 870 /* static */
 871 bool wxDateTime::IsDSTApplicable(int year, Country country)
 872 {
 873     if ( year == Inv_Year )
 874     {
 875         // take the current year if none given
 876         year = GetCurrentYear();
 877     }
 878
 879     if ( country == Country_Default )
 880     {
 881         country = GetCountry();
 882     }
 883
 884     switch ( country )
 885     {
 886         case USA:
 887         case UK:
 888             // DST was first observed in the US and UK during WWI, reused
 889             // during WWII and used again since 1966
 890             return year >= 1966 ||
 891                    (year >= 1942 && year <= 1945) ||
 892                    (year == 1918 || year == 1919);
 893
 894         default:
 895             // assume that it started after WWII
 896             return year > 1950;
 897     }
 898 }
 899
 900 /* static */
 901 wxDateTime wxDateTime::GetBeginDST(int year, Country country)
 902 {
 903     if ( year == Inv_Year )
 904     {
 905         // take the current year if none given
 906         year = GetCurrentYear();
 907     }
 908
 909     if ( country == Country_Default )
 910     {
 911         country = GetCountry();
 912     }
 913
 914     if ( !IsDSTApplicable(year, country) )
 915     {
 916         return wxInvalidDateTime;
 917     }
 918
 919     wxDateTime dt;
 920
 921     if ( IsWestEuropeanCountry(country) || (country == Russia) )
 922     {
 923         // DST begins at 1 a.m. GMT on the last Sunday of March
 924         if ( !dt.SetToLastWeekDay(Sun, Mar, year) )
 925         {
 926             // weird...
 927             wxFAIL_MSG( wxT("no last Sunday in March?") );
 928         }
 929
 930         dt += wxTimeSpan::Hours(1);
 931     }
 932     else switch ( country )
 933     {
 934         case USA:
 935             switch ( year )
 936             {
 937                 case 1918:
 938                 case 1919:
 939                     // don't know for sure - assume it was in effect all year
 940
 941                 case 1943:
 942                 case 1944:
 943                 case 1945:
 944                     dt.Set(1, Jan, year);
 945                     break;
 946
 947                 case 1942:
 948                     // DST was installed Feb 2, 1942 by the Congress
 949                     dt.Set(2, Feb, year);
 950                     break;
 951
 952                     // Oil embargo changed the DST period in the US
 953                 case 1974:
 954                     dt.Set(6, Jan, 1974);
 955                     break;
 956
 957                 case 1975:
 958                     dt.Set(23, Feb, 1975);
 959                     break;
 960
 961                 default:
 962                     // before 1986, DST begun on the last Sunday of April, but
 963                     // in 1986 Reagan changed it to begin at 2 a.m. of the
 964                     // first Sunday in April
 965                     if ( year < 1986 )
 966                     {
 967                         if ( !dt.SetToLastWeekDay(Sun, Apr, year) )
 968                         {
 969                             // weird...
 970                             wxFAIL_MSG( wxT("no first Sunday in April?") );
 971                         }
 972                     }
 973                     else if ( year > 2006 )
 974                     // Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005).
 975                     // Starting in 2007, daylight time begins in the United States on the
 976                     // second Sunday in March and ends on the first Sunday in November
 977                     {
 978                         if ( !dt.SetToWeekDay(Sun, 2, Mar, year) )
 979                         {
 980                             // weird...
 981                             wxFAIL_MSG( wxT("no second Sunday in March?") );
 982                         }
 983                     }
 984                     else
 985                     {
 986                         if ( !dt.SetToWeekDay(Sun, 1, Apr, year) )
 987                         {
 988                             // weird...
 989                             wxFAIL_MSG( wxT("no first Sunday in April?") );
 990                         }
 991                     }
 992
 993                     dt += wxTimeSpan::Hours(2);
 994
 995                     // TODO what about timezone??
 996             }
 997
 998             break;
 999
1000         default:
1001             // assume Mar 30 as the start of the DST for the rest of the world
1002             // - totally bogus, of course
1003             dt.Set(30, Mar, year);
1004     }
1005
1006     return dt;
1007 }
1008
1009 /* static */
1010 wxDateTime wxDateTime::GetEndDST(int year, Country country)
1011 {
1012     if ( year == Inv_Year )
1013     {
1014         // take the current year if none given
1015         year = GetCurrentYear();
1016     }
1017
1018     if ( country == Country_Default )
1019     {
1020         country = GetCountry();
1021     }
1022
1023     if ( !IsDSTApplicable(year, country) )
1024     {
1025         return wxInvalidDateTime;
1026     }
1027
1028     wxDateTime dt;
1029
1030     if ( IsWestEuropeanCountry(country) || (country == Russia) )
1031     {
1032         // DST ends at 1 a.m. GMT on the last Sunday of October
1033         if ( !dt.SetToLastWeekDay(Sun, Oct, year) )
1034         {
1035             // weirder and weirder...
1036             wxFAIL_MSG( wxT("no last Sunday in October?") );
1037         }
1038
1039         dt += wxTimeSpan::Hours(1);
1040     }
1041     else switch ( country )
1042     {
1043         case USA:
1044             switch ( year )
1045             {
1046                 case 1918:
1047                 case 1919:
1048                     // don't know for sure - assume it was in effect all year
1049
1050                 case 1943:
1051                 case 1944:
1052                     dt.Set(31, Dec, year);
1053                     break;
1054
1055                 case 1945:
1056                     // the time was reset after the end of the WWII
1057                     dt.Set(30, Sep, year);
1058                     break;
1059
1060                 default: // default for switch (year)
1061                     if ( year > 2006 )
1062                       // Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005).
1063                       // Starting in 2007, daylight time begins in the United States on the
1064                       // second Sunday in March and ends on the first Sunday in November
1065                     {
1066                         if ( !dt.SetToWeekDay(Sun, 1, Nov, year) )
1067                         {
1068                             // weird...
1069                             wxFAIL_MSG( wxT("no first Sunday in November?") );
1070                         }
1071                     }
1072                     else
1073                      // pre-2007
1074                      // DST ends at 2 a.m. on the last Sunday of October
1075                     {
1076                         if ( !dt.SetToLastWeekDay(Sun, Oct, year) )
1077                         {
1078                             // weirder and weirder...
1079                             wxFAIL_MSG( wxT("no last Sunday in October?") );
1080                         }
1081                     }
1082
1083                     dt += wxTimeSpan::Hours(2);
1084
1085             // TODO: what about timezone??
1086             }
1087             break;
1088
1089         default: // default for switch (country)
1090             // assume October 26th as the end of the DST - totally bogus too
1091             dt.Set(26, Oct, year);
1092     }
1093
1094     return dt;
1095 }
1096
1097 // ----------------------------------------------------------------------------
1098 // constructors and assignment operators
1099 // ----------------------------------------------------------------------------
1100
1101 // return the current time with ms precision
1102 /* static */ wxDateTime wxDateTime::UNow()
1103 {
1104     return wxDateTime(wxGetUTCTimeMillis());
1105 }
1106
1107 // the values in the tm structure contain the local time
1108 wxDateTime& wxDateTime::Set(const struct tm& tm)
1109 {
1110     struct tm tm2(tm);
1111     time_t timet = mktime(&tm2);
1112
1113     if ( timet == (time_t)-1 )
1114     {
1115         // mktime() rather unintuitively fails for Jan 1, 1970 if the hour is
1116         // less than timezone - try to make it work for this case
1117         if ( tm2.tm_year == 70 && tm2.tm_mon == 0 && tm2.tm_mday == 1 )
1118         {
1119             return Set((time_t)(
1120                        wxGetTimeZone() +
1121                        tm2.tm_hour * MIN_PER_HOUR * SEC_PER_MIN +
1122                        tm2.tm_min * SEC_PER_MIN +
1123                        tm2.tm_sec));
1124         }
1125
1126         wxFAIL_MSG( wxT("mktime() failed") );
1127
1128         *this = wxInvalidDateTime;
1129
1130         return *this;
1131     }
1132     else
1133     {
1134         return Set(timet);
1135     }
1136 }
1137
1138 wxDateTime& wxDateTime::Set(wxDateTime_t hour,
1139                             wxDateTime_t minute,
1140                             wxDateTime_t second,
1141                             wxDateTime_t millisec)
1142 {
1143     // we allow seconds to be 61 to account for the leap seconds, even if we
1144     // don't use them really
1145     wxDATETIME_CHECK( hour < 24 &&
1146                       second < 62 &&
1147                       minute < 60 &&
1148                       millisec < 1000,
1149                       wxT("Invalid time in wxDateTime::Set()") );
1150
1151     // get the current date from system
1152     struct tm tmstruct;
1153     struct tm *tm = GetTmNow(&tmstruct);
1154
1155     wxDATETIME_CHECK( tm, wxT("wxLocaltime_r() failed") );
1156
1157     // make a copy so it isn't clobbered by the call to mktime() below
1158     struct tm tm1(*tm);
1159
1160     // adjust the time
1161     tm1.tm_hour = hour;
1162     tm1.tm_min = minute;
1163     tm1.tm_sec = second;
1164
1165     // and the DST in case it changes on this date
1166     struct tm tm2(tm1);
1167     mktime(&tm2);
1168     if ( tm2.tm_isdst != tm1.tm_isdst )
1169         tm1.tm_isdst = tm2.tm_isdst;
1170
1171     (void)Set(tm1);
1172
1173     // and finally adjust milliseconds
1174     return SetMillisecond(millisec);
1175 }
1176
1177 wxDateTime& wxDateTime::Set(wxDateTime_t day,
1178                             Month        month,
1179                             int          year,
1180                             wxDateTime_t hour,
1181                             wxDateTime_t minute,
1182                             wxDateTime_t second,
1183                             wxDateTime_t millisec)
1184 {
1185     wxDATETIME_CHECK( hour < 24 &&
1186                       second < 62 &&
1187                       minute < 60 &&
1188                       millisec < 1000,
1189                       wxT("Invalid time in wxDateTime::Set()") );
1190
1191     ReplaceDefaultYearMonthWithCurrent(&year, &month);
1192
1193     wxDATETIME_CHECK( (0 < day) && (day <= GetNumberOfDays(month, year)),
1194                       wxT("Invalid date in wxDateTime::Set()") );
1195
1196     // the range of time_t type (inclusive)
1197     static const int yearMinInRange = 1970;
1198     static const int yearMaxInRange = 2037;
1199
1200     // test only the year instead of testing for the exact end of the Unix
1201     // time_t range - it doesn't bring anything to do more precise checks
1202     if ( year >= yearMinInRange && year <= yearMaxInRange )
1203     {
1204         // use the standard library version if the date is in range - this is
1205         // probably more efficient than our code
1206         struct tm tm;
1207         tm.tm_year = year - 1900;
1208         tm.tm_mon = month;
1209         tm.tm_mday = day;
1210         tm.tm_hour = hour;
1211         tm.tm_min = minute;
1212         tm.tm_sec = second;
1213         tm.tm_isdst = -1;       // mktime() will guess it
1214
1215         (void)Set(tm);
1216
1217         // and finally adjust milliseconds
1218         if (IsValid())
1219             SetMillisecond(millisec);
1220
1221         return *this;
1222     }
1223     else
1224     {
1225         // do time calculations ourselves: we want to calculate the number of
1226         // milliseconds between the given date and the epoch
1227
1228         // get the JDN for the midnight of this day
1229         m_time = GetTruncatedJDN(day, month, year);
1230         m_time -= EPOCH_JDN;
1231         m_time *= SECONDS_PER_DAY * TIME_T_FACTOR;
1232
1233         // JDN corresponds to GMT, we take localtime
1234         Add(wxTimeSpan(hour, minute, second + wxGetTimeZone(), millisec));
1235     }
1236
1237     return *this;
1238 }
1239
1240 wxDateTime& wxDateTime::Set(double jdn)
1241 {
1242     // so that m_time will be 0 for the midnight of Jan 1, 1970 which is jdn
1243     // EPOCH_JDN + 0.5
1244     jdn -= EPOCH_JDN + 0.5;
1245
1246     m_time.Assign(jdn*MILLISECONDS_PER_DAY);
1247
1248     // JDNs always are in UTC, so we don't need any adjustments for time zone
1249
1250     return *this;
1251 }
1252
1253 wxDateTime& wxDateTime::ResetTime()
1254 {
1255     Tm tm = GetTm();
1256
1257     if ( tm.hour || tm.min || tm.sec || tm.msec )
1258     {
1259         tm.msec =
1260         tm.sec =
1261         tm.min =
1262         tm.hour = 0;
1263
1264         Set(tm);
1265     }
1266
1267     return *this;
1268 }
1269
1270 wxDateTime wxDateTime::GetDateOnly() const
1271 {
1272     Tm tm = GetTm();
1273     tm.msec =
1274     tm.sec =
1275     tm.min =
1276     tm.hour = 0;
1277     return wxDateTime(tm);
1278 }
1279
1280 // ----------------------------------------------------------------------------
1281 // DOS Date and Time Format functions
1282 // ----------------------------------------------------------------------------
1283 // the dos date and time value is an unsigned 32 bit value in the format:
1284 // YYYYYYYMMMMDDDDDhhhhhmmmmmmsssss
1285 //
1286 // Y = year offset from 1980 (0-127)
1287 // M = month (1-12)
1288 // D = day of month (1-31)
1289 // h = hour (0-23)
1290 // m = minute (0-59)
1291 // s = bisecond (0-29) each bisecond indicates two seconds
1292 // ----------------------------------------------------------------------------
1293
1294 wxDateTime& wxDateTime::SetFromDOS(unsigned long ddt)
1295 {
1296     struct tm tm;
1297     InitTm(tm);
1298
1299     long year = ddt & 0xFE000000;
1300     year >>= 25;
1301     year += 80;
1302     tm.tm_year = year;
1303
1304     long month = ddt & 0x1E00000;
1305     month >>= 21;
1306     month -= 1;
1307     tm.tm_mon = month;
1308
1309     long day = ddt & 0x1F0000;
1310     day >>= 16;
1311     tm.tm_mday = day;
1312
1313     long hour = ddt & 0xF800;
1314     hour >>= 11;
1315     tm.tm_hour = hour;
1316
1317     long minute = ddt & 0x7E0;
1318     minute >>= 5;
1319     tm.tm_min = minute;
1320
1321     long second = ddt & 0x1F;
1322     tm.tm_sec = second * 2;
1323
1324     return Set(mktime(&tm));
1325 }
1326
1327 unsigned long wxDateTime::GetAsDOS() const
1328 {
1329     unsigned long ddt;
1330     time_t ticks = GetTicks();
1331     struct tm tmstruct;
1332     struct tm *tm = wxLocaltime_r(&ticks, &tmstruct);
1333     wxCHECK_MSG( tm, ULONG_MAX, wxT("time can't be represented in DOS format") );
1334
1335     long year = tm->tm_year;
1336     year -= 80;
1337     year <<= 25;
1338
1339     long month = tm->tm_mon;
1340     month += 1;
1341     month <<= 21;
1342
1343     long day = tm->tm_mday;
1344     day <<= 16;
1345
1346     long hour = tm->tm_hour;
1347     hour <<= 11;
1348
1349     long minute = tm->tm_min;
1350     minute <<= 5;
1351
1352     long second = tm->tm_sec;
1353     second /= 2;
1354
1355     ddt = year | month | day | hour | minute | second;
1356     return ddt;
1357 }
1358
1359 // ----------------------------------------------------------------------------
1360 // time_t <-> broken down time conversions
1361 // ----------------------------------------------------------------------------
1362
1363 wxDateTime::Tm wxDateTime::GetTm(const TimeZone& tz) const
1364 {
1365     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1366
1367     time_t time = GetTicks();
1368     if ( time != (time_t)-1 )
1369     {
1370         // use C RTL functions
1371         struct tm tmstruct;
1372         tm *tm;
1373         if ( tz.GetOffset() == -wxGetTimeZone() )
1374         {
1375             // we are working with local time
1376             tm = wxLocaltime_r(&time, &tmstruct);
1377
1378             // should never happen
1379             wxCHECK_MSG( tm, Tm(), wxT("wxLocaltime_r() failed") );
1380         }
1381         else
1382         {
1383             time += (time_t)tz.GetOffset();
1384 #if defined(__VMS__) || defined(__WATCOMC__) // time is unsigned so avoid warning
1385             int time2 = (int) time;
1386             if ( time2 >= 0 )
1387 #else
1388             if ( time >= 0 )
1389 #endif
1390             {
1391                 tm = wxGmtime_r(&time, &tmstruct);
1392
1393                 // should never happen
1394                 wxCHECK_MSG( tm, Tm(), wxT("wxGmtime_r() failed") );
1395             }
1396             else
1397             {
1398                 tm = (struct tm *)NULL;
1399             }
1400         }
1401
1402         if ( tm )
1403         {
1404             // adjust the milliseconds
1405             Tm tm2(*tm, tz);
1406             long timeOnly = (m_time % MILLISECONDS_PER_DAY).ToLong();
1407             tm2.msec = (wxDateTime_t)(timeOnly % 1000);
1408             return tm2;
1409         }
1410         //else: use generic code below
1411     }
1412
1413     // remember the time and do the calculations with the date only - this
1414     // eliminates rounding errors of the floating point arithmetics
1415
1416     wxLongLong timeMidnight = m_time + tz.GetOffset() * 1000;
1417
1418     long timeOnly = (timeMidnight % MILLISECONDS_PER_DAY).ToLong();
1419
1420     // we want to always have positive time and timeMidnight to be really
1421     // the midnight before it
1422     if ( timeOnly < 0 )
1423     {
1424         timeOnly = MILLISECONDS_PER_DAY + timeOnly;
1425     }
1426
1427     timeMidnight -= timeOnly;
1428
1429     // calculate the Gregorian date from JDN for the midnight of our date:
1430     // this will yield day, month (in 1..12 range) and year
1431
1432     // actually, this is the JDN for the noon of the previous day
1433     long jdn = (timeMidnight / MILLISECONDS_PER_DAY).ToLong() + EPOCH_JDN;
1434
1435     // CREDIT: code below is by Scott E. Lee (but bugs are mine)
1436
1437     wxASSERT_MSG( jdn > -2, wxT("JDN out of range") );
1438
1439     // calculate the century
1440     long temp = (jdn + JDN_OFFSET) * 4 - 1;
1441     long century = temp / DAYS_PER_400_YEARS;
1442
1443     // then the year and day of year (1 <= dayOfYear <= 366)
1444     temp = ((temp % DAYS_PER_400_YEARS) / 4) * 4 + 3;
1445     long year = (century * 100) + (temp / DAYS_PER_4_YEARS);
1446     long dayOfYear = (temp % DAYS_PER_4_YEARS) / 4 + 1;
1447
1448     // and finally the month and day of the month
1449     temp = dayOfYear * 5 - 3;
1450     long month = temp / DAYS_PER_5_MONTHS;
1451     long day = (temp % DAYS_PER_5_MONTHS) / 5 + 1;
1452
1453     // month is counted from March - convert to normal
1454     if ( month < 10 )
1455     {
1456         month += 3;
1457     }
1458     else
1459     {
1460         year += 1;
1461         month -= 9;
1462     }
1463
1464     // year is offset by 4800
1465     year -= 4800;
1466
1467     // check that the algorithm gave us something reasonable
1468     wxASSERT_MSG( (0 < month) && (month <= 12), wxT("invalid month") );
1469     wxASSERT_MSG( (1 <= day) && (day < 32), wxT("invalid day") );
1470
1471     // construct Tm from these values
1472     Tm tm;
1473     tm.year = (int)year;
1474     tm.yday = (wxDateTime_t)(dayOfYear - 1); // use C convention for day number
1475     tm.mon = (Month)(month - 1); // algorithm yields 1 for January, not 0
1476     tm.mday = (wxDateTime_t)day;
1477     tm.msec = (wxDateTime_t)(timeOnly % 1000);
1478     timeOnly -= tm.msec;
1479     timeOnly /= 1000;               // now we have time in seconds
1480
1481     tm.sec = (wxDateTime_t)(timeOnly % SEC_PER_MIN);
1482     timeOnly -= tm.sec;
1483     timeOnly /= SEC_PER_MIN;        // now we have time in minutes
1484
1485     tm.min = (wxDateTime_t)(timeOnly % MIN_PER_HOUR);
1486     timeOnly -= tm.min;
1487
1488     tm.hour = (wxDateTime_t)(timeOnly / MIN_PER_HOUR);
1489
1490     return tm;
1491 }
1492
1493 wxDateTime& wxDateTime::SetYear(int year)
1494 {
1495     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1496
1497     Tm tm(GetTm());
1498     tm.year = year;
1499     Set(tm);
1500
1501     return *this;
1502 }
1503
1504 wxDateTime& wxDateTime::SetMonth(Month month)
1505 {
1506     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1507
1508     Tm tm(GetTm());
1509     tm.mon = month;
1510     Set(tm);
1511
1512     return *this;
1513 }
1514
1515 wxDateTime& wxDateTime::SetDay(wxDateTime_t mday)
1516 {
1517     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1518
1519     Tm tm(GetTm());
1520     tm.mday = mday;
1521     Set(tm);
1522
1523     return *this;
1524 }
1525
1526 wxDateTime& wxDateTime::SetHour(wxDateTime_t hour)
1527 {
1528     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1529
1530     Tm tm(GetTm());
1531     tm.hour = hour;
1532     Set(tm);
1533
1534     return *this;
1535 }
1536
1537 wxDateTime& wxDateTime::SetMinute(wxDateTime_t min)
1538 {
1539     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1540
1541     Tm tm(GetTm());
1542     tm.min = min;
1543     Set(tm);
1544
1545     return *this;
1546 }
1547
1548 wxDateTime& wxDateTime::SetSecond(wxDateTime_t sec)
1549 {
1550     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1551
1552     Tm tm(GetTm());
1553     tm.sec = sec;
1554     Set(tm);
1555
1556     return *this;
1557 }
1558
1559 wxDateTime& wxDateTime::SetMillisecond(wxDateTime_t millisecond)
1560 {
1561     wxASSERT_MSG( IsValid(), wxT("invalid wxDateTime") );
1562
1563     // we don't need to use GetTm() for this one
1564     m_time -= m_time % 1000l;
1565     m_time += millisecond;
1566
1567     return *this;
1568 }
1569
1570 // ----------------------------------------------------------------------------
1571 // wxDateTime arithmetics
1572 // ----------------------------------------------------------------------------
1573
1574 wxDateTime& wxDateTime::Add(const wxDateSpan& diff)
1575 {
1576     Tm tm(GetTm());
1577
1578     tm.year += diff.GetYears();
1579     tm.AddMonths(diff.GetMonths());
1580
1581     // check that the resulting date is valid
1582     if ( tm.mday > GetNumOfDaysInMonth(tm.year, tm.mon) )
1583     {
1584         // We suppose that when adding one month to Jan 31 we want to get Feb
1585         // 28 (or 29), i.e. adding a month to the last day of the month should
1586         // give the last day of the next month which is quite logical.
1587         //
1588         // Unfortunately, there is no logic way to understand what should
1589         // Jan 30 + 1 month be - Feb 28 too or Feb 27 (assuming non leap year)?
1590         // We make it Feb 28 (last day too), but it is highly questionable.
1591         tm.mday = GetNumOfDaysInMonth(tm.year, tm.mon);
1592     }
1593
1594     tm.AddDays(diff.GetTotalDays());
1595
1596     Set(tm);
1597
1598     wxASSERT_MSG( IsSameTime(tm),
1599                   wxT("Add(wxDateSpan) shouldn't modify time") );
1600
1601     return *this;
1602 }
1603
1604 wxDateSpan wxDateTime::DiffAsDateSpan(const wxDateTime& dt) const
1605 {
1606     wxASSERT_MSG( IsValid() && dt.IsValid(), wxT("invalid wxDateTime"));
1607
1608     // If dt is larger than this, calculations below needs to be inverted.
1609     int inv = 1;
1610     if ( dt > *this )
1611         inv = -1;
1612
1613     int y = GetYear() - dt.GetYear();
1614     int m = GetMonth() - dt.GetMonth();
1615     int d = GetDay() - dt.GetDay();
1616
1617     // If month diff is negative, dt is the year before, so decrease year
1618     // and set month diff to its inverse, e.g. January - December should be 1,
1619     // not -11.
1620     if ( m * inv < 0 || (m == 0 && d * inv < 0))
1621     {
1622         m += inv * MONTHS_IN_YEAR;
1623         y -= inv;
1624     }
1625
1626     // Same logic for days as for months above.
1627     if ( d * inv < 0 )
1628     {
1629         // Use number of days in month from the month which end date we're
1630         // crossing. That is month before this for positive diff, and this
1631         // month for negative diff.
1632         // If we're on january and using previous month, we get december
1633         // previous year, but don't care, december has same amount of days
1634         // every year.
1635         wxDateTime::Month monthfordays = GetMonth();
1636         if (inv > 0 && monthfordays == wxDateTime::Jan)
1637             monthfordays = wxDateTime::Dec;
1638         else if (inv > 0)
1639             monthfordays = static_cast<wxDateTime::Month>(monthfordays - 1);
1640
1641         d += inv * wxDateTime::GetNumberOfDays(monthfordays, GetYear());
1642         m -= inv;
1643     }
1644
1645     int w =  d / DAYS_PER_WEEK;
1646
1647     // Remove weeks from d, since wxDateSpan only keep days as the ones
1648     // not in complete weeks
1649     d -= w * DAYS_PER_WEEK;
1650
1651     return wxDateSpan(y, m, w, d);
1652 }
1653
1654 // ----------------------------------------------------------------------------
1655 // Weekday and monthday stuff
1656 // ----------------------------------------------------------------------------
1657
1658 // convert Sun, Mon, ..., Sat into 6, 0, ..., 5
1659 static inline int ConvertWeekDayToMondayBase(int wd)
1660 {
1661     return wd == wxDateTime::Sun ? 6 : wd - 1;
1662 }
1663
1664 /* static */
1665 wxDateTime
1666 wxDateTime::SetToWeekOfYear(int year, wxDateTime_t numWeek, WeekDay wd)
1667 {
1668     wxASSERT_MSG( numWeek > 0,
1669                   wxT("invalid week number: weeks are counted from 1") );
1670
1671     // Jan 4 always lies in the 1st week of the year
1672     wxDateTime dt(4, Jan, year);
1673     dt.SetToWeekDayInSameWeek(wd);
1674     dt += wxDateSpan::Weeks(numWeek - 1);
1675
1676     return dt;
1677 }
1678
1679 #if WXWIN_COMPATIBILITY_2_6
1680 // use a separate function to avoid warnings about using deprecated
1681 // SetToTheWeek in GetWeek below
1682 static wxDateTime
1683 SetToTheWeek(int year,
1684              wxDateTime::wxDateTime_t numWeek,
1685              wxDateTime::WeekDay weekday,
1686              wxDateTime::WeekFlags flags)
1687 {
1688     // Jan 4 always lies in the 1st week of the year
1689     wxDateTime dt(4, wxDateTime::Jan, year);
1690     dt.SetToWeekDayInSameWeek(weekday, flags);
1691     dt += wxDateSpan::Weeks(numWeek - 1);
1692
1693     return dt;
1694 }
1695
1696 bool wxDateTime::SetToTheWeek(wxDateTime_t numWeek,
1697                               WeekDay weekday,
1698                               WeekFlags flags)
1699 {
1700     int year = GetYear();
1701     *this = ::SetToTheWeek(year, numWeek, weekday, flags);
1702     if ( GetYear() != year )
1703     {
1704         // oops... numWeek was too big
1705         return false;
1706     }
1707
1708     return true;
1709 }
1710
1711 wxDateTime wxDateTime::GetWeek(wxDateTime_t numWeek,
1712                                WeekDay weekday,
1713                                WeekFlags flags) const
1714 {
1715     return ::SetToTheWeek(GetYear(), numWeek, weekday, flags);
1716 }
1717 #endif // WXWIN_COMPATIBILITY_2_6
1718
1719 wxDateTime& wxDateTime::SetToLastMonthDay(Month month,
1720                                           int year)
1721 {
1722     // take the current month/year if none specified
1723     if ( year == Inv_Year )
1724         year = GetYear();
1725     if ( month == Inv_Month )
1726         month = GetMonth();
1727
1728     return Set(GetNumOfDaysInMonth(year, month), month, year);
1729 }
1730
1731 wxDateTime& wxDateTime::SetToWeekDayInSameWeek(WeekDay weekday, WeekFlags flags)
1732 {
1733     wxDATETIME_CHECK( weekday != Inv_WeekDay, wxT("invalid weekday") );
1734
1735     int wdayDst = weekday,
1736         wdayThis = GetWeekDay();
1737     if ( wdayDst == wdayThis )
1738     {
1739         // nothing to do
1740         return *this;
1741     }
1742
1743     if ( flags == Default_First )
1744     {
1745         flags = GetCountry() == USA ? Sunday_First : Monday_First;
1746     }
1747
1748     // the logic below based on comparing weekday and wdayThis works if Sun (0)
1749     // is the first day in the week, but breaks down for Monday_First case so
1750     // we adjust the week days in this case
1751     if ( flags == Monday_First )
1752     {
1753         if ( wdayThis == Sun )
1754             wdayThis += 7;
1755         if ( wdayDst == Sun )
1756             wdayDst += 7;
1757     }
1758     //else: Sunday_First, nothing to do
1759
1760     // go forward or back in time to the day we want
1761     if ( wdayDst < wdayThis )
1762     {
1763         return Subtract(wxDateSpan::Days(wdayThis - wdayDst));
1764     }
1765     else // weekday > wdayThis
1766     {
1767         return Add(wxDateSpan::Days(wdayDst - wdayThis));
1768     }
1769 }
1770
1771 wxDateTime& wxDateTime::SetToNextWeekDay(WeekDay weekday)
1772 {
1773     wxDATETIME_CHECK( weekday != Inv_WeekDay, wxT("invalid weekday") );
1774
1775     int diff;
1776     WeekDay wdayThis = GetWeekDay();
1777     if ( weekday == wdayThis )
1778     {
1779         // nothing to do
1780         return *this;
1781     }
1782     else if ( weekday < wdayThis )
1783     {
1784         // need to advance a week
1785         diff = 7 - (wdayThis - weekday);
1786     }
1787     else // weekday > wdayThis
1788     {
1789         diff = weekday - wdayThis;
1790     }
1791
1792     return Add(wxDateSpan::Days(diff));
1793 }
1794
1795 wxDateTime& wxDateTime::SetToPrevWeekDay(WeekDay weekday)
1796 {
1797     wxDATETIME_CHECK( weekday != Inv_WeekDay, wxT("invalid weekday") );
1798
1799     int diff;
1800     WeekDay wdayThis = GetWeekDay();
1801     if ( weekday == wdayThis )
1802     {
1803         // nothing to do
1804         return *this;
1805     }
1806     else if ( weekday > wdayThis )
1807     {
1808         // need to go to previous week
1809         diff = 7 - (weekday - wdayThis);
1810     }
1811     else // weekday < wdayThis
1812     {
1813         diff = wdayThis - weekday;
1814     }
1815
1816     return Subtract(wxDateSpan::Days(diff));
1817 }
1818
1819 bool wxDateTime::SetToWeekDay(WeekDay weekday,
1820                               int n,
1821                               Month month,
1822                               int year)
1823 {
1824     wxCHECK_MSG( weekday != Inv_WeekDay, false, wxT("invalid weekday") );
1825
1826     // we don't check explicitly that -5 <= n <= 5 because we will return false
1827     // anyhow in such case - but may be should still give an assert for it?
1828
1829     // take the current month/year if none specified
1830     ReplaceDefaultYearMonthWithCurrent(&year, &month);
1831
1832     wxDateTime dt;
1833
1834     // TODO this probably could be optimised somehow...
1835
1836     if ( n > 0 )
1837     {
1838         // get the first day of the month
1839         dt.Set(1, month, year);
1840
1841         // get its wday
1842         WeekDay wdayFirst = dt.GetWeekDay();
1843
1844         // go to the first weekday of the month
1845         int diff = weekday - wdayFirst;
1846         if ( diff < 0 )
1847             diff += 7;
1848
1849         // add advance n-1 weeks more
1850         diff += 7*(n - 1);
1851
1852         dt += wxDateSpan::Days(diff);
1853     }
1854     else // count from the end of the month
1855     {
1856         // get the last day of the month
1857         dt.SetToLastMonthDay(month, year);
1858
1859         // get its wday
1860         WeekDay wdayLast = dt.GetWeekDay();
1861
1862         // go to the last weekday of the month
1863         int diff = wdayLast - weekday;
1864         if ( diff < 0 )
1865             diff += 7;
1866
1867         // and rewind n-1 weeks from there
1868         diff += 7*(-n - 1);
1869
1870         dt -= wxDateSpan::Days(diff);
1871     }
1872
1873     // check that it is still in the same month
1874     if ( dt.GetMonth() == month )
1875     {
1876         *this = dt;
1877
1878         return true;
1879     }
1880     else
1881     {
1882         // no such day in this month
1883         return false;
1884     }
1885 }
1886
1887 static inline
1888 wxDateTime::wxDateTime_t GetDayOfYearFromTm(const wxDateTime::Tm& tm)
1889 {
1890     return (wxDateTime::wxDateTime_t)(gs_cumulatedDays[wxDateTime::IsLeapYear(tm.year)][tm.mon] + tm.mday);
1891 }
1892
1893 wxDateTime::wxDateTime_t wxDateTime::GetDayOfYear(const TimeZone& tz) const
1894 {
1895     return GetDayOfYearFromTm(GetTm(tz));
1896 }
1897
1898 wxDateTime::wxDateTime_t
1899 wxDateTime::GetWeekOfYear(wxDateTime::WeekFlags flags, const TimeZone& tz) const
1900 {
1901     if ( flags == Default_First )
1902     {
1903         flags = GetCountry() == USA ? Sunday_First : Monday_First;
1904     }
1905
1906     Tm tm(GetTm(tz));
1907     wxDateTime_t nDayInYear = GetDayOfYearFromTm(tm);
1908
1909     int wdTarget = GetWeekDay(tz);
1910     int wdYearStart = wxDateTime(1, Jan, GetYear()).GetWeekDay();
1911     int week;
1912     if ( flags == Sunday_First )
1913     {
1914         // FIXME: First week is not calculated correctly.
1915         week = (nDayInYear - wdTarget + 7) / 7;
1916         if ( wdYearStart == Wed || wdYearStart == Thu )
1917             week++;
1918     }
1919     else // week starts with monday
1920     {
1921         // adjust the weekdays to non-US style.
1922         wdYearStart = ConvertWeekDayToMondayBase(wdYearStart);
1923
1924         // quoting from http://www.cl.cam.ac.uk/~mgk25/iso-time.html:
1925         //
1926         //      Week 01 of a year is per definition the first week that has the
1927         //      Thursday in this year, which is equivalent to the week that
1928         //      contains the fourth day of January. In other words, the first
1929         //      week of a new year is the week that has the majority of its
1930         //      days in the new year. Week 01 might also contain days from the
1931         //      previous year and the week before week 01 of a year is the last
1932         //      week (52 or 53) of the previous year even if it contains days
1933         //      from the new year. A week starts with Monday (day 1) and ends
1934         //      with Sunday (day 7).
1935         //
1936
1937         // if Jan 1 is Thursday or less, it is in the first week of this year
1938         int dayCountFix = wdYearStart < 4 ? 6 : -1;
1939
1940         // count the number of week
1941         week = (nDayInYear + wdYearStart + dayCountFix) / DAYS_PER_WEEK;
1942
1943         // check if we happen to be at the last week of previous year:
1944         if ( week == 0 )
1945         {
1946             week = wxDateTime(31, Dec, GetYear() - 1).GetWeekOfYear();
1947         }
1948         else if ( week == 53 )
1949         {
1950             int wdYearEnd = (wdYearStart + 364 + IsLeapYear(GetYear()))
1951                                 % DAYS_PER_WEEK;
1952
1953             // Week 53 only if last day of year is Thursday or later.
1954             if ( wdYearEnd < 3 )
1955                 week = 1;
1956         }
1957     }
1958
1959     return (wxDateTime::wxDateTime_t)week;
1960 }
1961
1962 wxDateTime::wxDateTime_t wxDateTime::GetWeekOfMonth(wxDateTime::WeekFlags flags,
1963                                                     const TimeZone& tz) const
1964 {
1965     Tm tm = GetTm(tz);
1966     const wxDateTime dateFirst = wxDateTime(1, tm.mon, tm.year);
1967     const wxDateTime::WeekDay wdFirst = dateFirst.GetWeekDay();
1968
1969     if ( flags == Default_First )
1970     {
1971         flags = GetCountry() == USA ? Sunday_First : Monday_First;
1972     }
1973
1974     // compute offset of dateFirst from the beginning of the week
1975     int firstOffset;
1976     if ( flags == Sunday_First )
1977         firstOffset = wdFirst - Sun;
1978     else
1979         firstOffset = wdFirst == Sun ? DAYS_PER_WEEK - 1 : wdFirst - Mon;
1980
1981     return (wxDateTime::wxDateTime_t)((tm.mday - 1 + firstOffset)/7 + 1);
1982 }
1983
1984 wxDateTime& wxDateTime::SetToYearDay(wxDateTime::wxDateTime_t yday)
1985 {
1986     int year = GetYear();
1987     wxDATETIME_CHECK( (0 < yday) && (yday <= GetNumberOfDays(year)),
1988                       wxT("invalid year day") );
1989
1990     bool isLeap = IsLeapYear(year);
1991     for ( Month mon = Jan; mon < Inv_Month; wxNextMonth(mon) )
1992     {
1993         // for Dec, we can't compare with gs_cumulatedDays[mon + 1], but we
1994         // don't need it neither - because of the CHECK above we know that
1995         // yday lies in December then
1996         if ( (mon == Dec) || (yday <= gs_cumulatedDays[isLeap][mon + 1]) )
1997         {
1998             Set((wxDateTime::wxDateTime_t)(yday - gs_cumulatedDays[isLeap][mon]), mon, year);
1999
2000             break;
2001         }
2002     }
2003
2004     return *this;
2005 }
2006
2007 // ----------------------------------------------------------------------------
2008 // Julian day number conversion and related stuff
2009 // ----------------------------------------------------------------------------
2010
2011 double wxDateTime::GetJulianDayNumber() const
2012 {
2013     return m_time.ToDouble() / MILLISECONDS_PER_DAY + EPOCH_JDN + 0.5;
2014 }
2015
2016 double wxDateTime::GetRataDie() const
2017 {
2018     // March 1 of the year 0 is Rata Die day -306 and JDN 1721119.5
2019     return GetJulianDayNumber() - 1721119.5 - 306;
2020 }
2021
2022 // ----------------------------------------------------------------------------
2023 // timezone and DST stuff
2024 // ----------------------------------------------------------------------------
2025
2026 int wxDateTime::IsDST(wxDateTime::Country country) const
2027 {
2028     wxCHECK_MSG( country == Country_Default, -1,
2029                  wxT("country support not implemented") );
2030
2031     // use the C RTL for the dates in the standard range
2032     time_t timet = GetTicks();
2033     if ( timet != (time_t)-1 )
2034     {
2035         struct tm tmstruct;
2036         tm *tm = wxLocaltime_r(&timet, &tmstruct);
2037
2038         wxCHECK_MSG( tm, -1, wxT("wxLocaltime_r() failed") );
2039
2040         return tm->tm_isdst;
2041     }
2042     else
2043     {
2044         int year = GetYear();
2045
2046         if ( !IsDSTApplicable(year, country) )
2047         {
2048             // no DST time in this year in this country
2049             return -1;
2050         }
2051
2052         return IsBetween(GetBeginDST(year, country), GetEndDST(year, country));
2053     }
2054 }
2055
2056 wxDateTime& wxDateTime::MakeTimezone(const TimeZone& tz, bool noDST)
2057 {
2058     long secDiff = wxGetTimeZone() + tz.GetOffset();
2059
2060     // we need to know whether DST is or not in effect for this date unless
2061     // the test disabled by the caller
2062     if ( !noDST && (IsDST() == 1) )
2063     {
2064         // FIXME we assume that the DST is always shifted by 1 hour
2065         secDiff -= 3600;
2066     }
2067
2068     return Add(wxTimeSpan::Seconds(secDiff));
2069 }
2070
2071 wxDateTime& wxDateTime::MakeFromTimezone(const TimeZone& tz, bool noDST)
2072 {
2073     long secDiff = wxGetTimeZone() + tz.GetOffset();
2074
2075     // we need to know whether DST is or not in effect for this date unless
2076     // the test disabled by the caller
2077     if ( !noDST && (IsDST() == 1) )
2078     {
2079         // FIXME we assume that the DST is always shifted by 1 hour
2080         secDiff -= 3600;
2081     }
2082
2083     return Subtract(wxTimeSpan::Seconds(secDiff));
2084 }
2085
2086 // ============================================================================
2087 // wxDateTimeHolidayAuthority and related classes
2088 // ============================================================================
2089
2090 #include "wx/arrimpl.cpp"
2091
2092 WX_DEFINE_OBJARRAY(wxDateTimeArray)
2093
2094 static int wxCMPFUNC_CONV
2095 wxDateTimeCompareFunc(wxDateTime **first, wxDateTime **second)
2096 {
2097     wxDateTime dt1 = **first,
2098                dt2 = **second;
2099
2100     return dt1 == dt2 ? 0 : dt1 < dt2 ? -1 : +1;
2101 }
2102
2103 // ----------------------------------------------------------------------------
2104 // wxDateTimeHolidayAuthority
2105 // ----------------------------------------------------------------------------
2106
2107 wxHolidayAuthoritiesArray wxDateTimeHolidayAuthority::ms_authorities;
2108
2109 /* static */
2110 bool wxDateTimeHolidayAuthority::IsHoliday(const wxDateTime& dt)
2111 {
2112     size_t count = ms_authorities.size();
2113     for ( size_t n = 0; n < count; n++ )
2114     {
2115         if ( ms_authorities[n]->DoIsHoliday(dt) )
2116         {
2117             return true;
2118         }
2119     }
2120
2121     return false;
2122 }
2123
2124 /* static */
2125 size_t
2126 wxDateTimeHolidayAuthority::GetHolidaysInRange(const wxDateTime& dtStart,
2127                                                const wxDateTime& dtEnd,
2128                                                wxDateTimeArray& holidays)
2129 {
2130     wxDateTimeArray hol;
2131
2132     holidays.Clear();
2133
2134     const size_t countAuth = ms_authorities.size();
2135     for ( size_t nAuth = 0; nAuth < countAuth; nAuth++ )
2136     {
2137         ms_authorities[nAuth]->DoGetHolidaysInRange(dtStart, dtEnd, hol);
2138
2139         WX_APPEND_ARRAY(holidays, hol);
2140     }
2141
2142     holidays.Sort(wxDateTimeCompareFunc);
2143
2144     return holidays.size();
2145 }
2146
2147 /* static */
2148 void wxDateTimeHolidayAuthority::ClearAllAuthorities()
2149 {
2150     WX_CLEAR_ARRAY(ms_authorities);
2151 }
2152
2153 /* static */
2154 void wxDateTimeHolidayAuthority::AddAuthority(wxDateTimeHolidayAuthority *auth)
2155 {
2156     ms_authorities.push_back(auth);
2157 }
2158
2159 wxDateTimeHolidayAuthority::~wxDateTimeHolidayAuthority()
2160 {
2161     // required here for Darwin
2162 }
2163
2164 // ----------------------------------------------------------------------------
2165 // wxDateTimeWorkDays
2166 // ----------------------------------------------------------------------------
2167
2168 bool wxDateTimeWorkDays::DoIsHoliday(const wxDateTime& dt) const
2169 {
2170     wxDateTime::WeekDay wd = dt.GetWeekDay();
2171
2172     return (wd == wxDateTime::Sun) || (wd == wxDateTime::Sat);
2173 }
2174
2175 size_t wxDateTimeWorkDays::DoGetHolidaysInRange(const wxDateTime& dtStart,
2176                                                 const wxDateTime& dtEnd,
2177                                                 wxDateTimeArray& holidays) const
2178 {
2179     if ( dtStart > dtEnd )
2180     {
2181         wxFAIL_MSG( wxT("invalid date range in GetHolidaysInRange") );
2182
2183         return 0u;
2184     }
2185
2186     holidays.Empty();
2187
2188     // instead of checking all days, start with the first Sat after dtStart and
2189     // end with the last Sun before dtEnd
2190     wxDateTime dtSatFirst = dtStart.GetNextWeekDay(wxDateTime::Sat),
2191                dtSatLast = dtEnd.GetPrevWeekDay(wxDateTime::Sat),
2192                dtSunFirst = dtStart.GetNextWeekDay(wxDateTime::Sun),
2193                dtSunLast = dtEnd.GetPrevWeekDay(wxDateTime::Sun),
2194                dt;
2195
2196     for ( dt = dtSatFirst; dt <= dtSatLast; dt += wxDateSpan::Week() )
2197     {
2198         holidays.Add(dt);
2199     }
2200
2201     for ( dt = dtSunFirst; dt <= dtSunLast; dt += wxDateSpan::Week() )
2202     {
2203         holidays.Add(dt);
2204     }
2205
2206     return holidays.GetCount();
2207 }
2208
2209 // ============================================================================
2210 // other helper functions
2211 // ============================================================================
2212
2213 // ----------------------------------------------------------------------------
2214 // iteration helpers: can be used to write a for loop over enum variable like
2215 // this:
2216 //  for ( m = wxDateTime::Jan; m < wxDateTime::Inv_Month; wxNextMonth(m) )
2217 // ----------------------------------------------------------------------------
2218
2219 WXDLLIMPEXP_BASE void wxNextMonth(wxDateTime::Month& m)
2220 {
2221     wxASSERT_MSG( m < wxDateTime::Inv_Month, wxT("invalid month") );
2222
2223     // no wrapping or the for loop above would never end!
2224     m = (wxDateTime::Month)(m + 1);
2225 }
2226
2227 WXDLLIMPEXP_BASE void wxPrevMonth(wxDateTime::Month& m)
2228 {
2229     wxASSERT_MSG( m < wxDateTime::Inv_Month, wxT("invalid month") );
2230
2231     m = m == wxDateTime::Jan ? wxDateTime::Inv_Month
2232                              : (wxDateTime::Month)(m - 1);
2233 }
2234
2235 WXDLLIMPEXP_BASE void wxNextWDay(wxDateTime::WeekDay& wd)
2236 {
2237     wxASSERT_MSG( wd < wxDateTime::Inv_WeekDay, wxT("invalid week day") );
2238
2239     // no wrapping or the for loop above would never end!
2240     wd = (wxDateTime::WeekDay)(wd + 1);
2241 }
2242
2243 WXDLLIMPEXP_BASE void wxPrevWDay(wxDateTime::WeekDay& wd)
2244 {
2245     wxASSERT_MSG( wd < wxDateTime::Inv_WeekDay, wxT("invalid week day") );
2246
2247     wd = wd == wxDateTime::Sun ? wxDateTime::Inv_WeekDay
2248                                : (wxDateTime::WeekDay)(wd - 1);
2249 }
2250
2251 #ifdef __WINDOWS__
2252
2253 wxDateTime& wxDateTime::SetFromMSWSysTime(const SYSTEMTIME& st)
2254 {
2255     return Set(st.wDay,
2256             static_cast<wxDateTime::Month>(wxDateTime::Jan + st.wMonth - 1),
2257             st.wYear,
2258             st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
2259 }
2260
2261 wxDateTime& wxDateTime::SetFromMSWSysDate(const SYSTEMTIME& st)
2262 {
2263     return Set(st.wDay,
2264             static_cast<wxDateTime::Month>(wxDateTime::Jan + st.wMonth - 1),
2265             st.wYear,
2266             0, 0, 0, 0);
2267 }
2268
2269 void wxDateTime::GetAsMSWSysTime(SYSTEMTIME* st) const
2270 {
2271     const wxDateTime::Tm tm(GetTm());
2272
2273     st->wYear = (WXWORD)tm.year;
2274     st->wMonth = (WXWORD)(tm.mon - wxDateTime::Jan + 1);
2275     st->wDay = tm.mday;
2276
2277     st->wDayOfWeek = 0;
2278     st->wHour = tm.hour;
2279     st->wMinute = tm.min;
2280     st->wSecond = tm.sec;
2281     st->wMilliseconds = tm.msec;
2282 }
2283
2284 void wxDateTime::GetAsMSWSysDate(SYSTEMTIME* st) const
2285 {
2286     const wxDateTime::Tm tm(GetTm());
2287
2288     st->wYear = (WXWORD)tm.year;
2289     st->wMonth = (WXWORD)(tm.mon - wxDateTime::Jan + 1);
2290     st->wDay = tm.mday;
2291
2292     st->wDayOfWeek =
2293     st->wHour =
2294     st->wMinute =
2295     st->wSecond =
2296     st->wMilliseconds = 0;
2297 }
2298
2299 #endif // __WINDOWS__
2300
2301 #endif // wxUSE_DATETIME