-/////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
// Name: wx/datetime.h
// Purpose: implementation of time/date related classes
// Author: Vadim Zeitlin
// Modified by:
// Created: 11.05.99
// RCS-ID: $Id$
-// Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
+// Copyright: (c) 1999 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
+// parts of code taken from sndcal library by Scott E. Lee:
+//
+// Copyright 1993-1995, Scott E. Lee, all rights reserved.
+// Permission granted to use, copy, modify, distribute and sell
+// so long as the above copyright and this permission statement
+// are retained in all copies.
+//
// Licence: wxWindows license
-/////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+/*
+ * Implementation notes:
+ *
+ * 1. the time is stored as a 64bit integer containing the signed number of
+ * milliseconds since Jan 1. 1970 (the Unix Epoch) - so it is always
+ * expressed in GMT.
+ *
+ * 2. the range is thus something about 580 million years, but due to current
+ * algorithms limitations, only dates from Nov 24, 4714BC are handled
+ *
+ * 3. standard ANSI C functions are used to do time calculations whenever
+ * possible, i.e. when the date is in the range Jan 1, 1970 to 2038
+ *
+ * 4. otherwise, the calculations are done by converting the date to/from JDN
+ * first (the range limitation mentioned above comes from here: the
+ * algorithm used by Scott E. Lee's code only works for positive JDNs, more
+ * or less)
+ *
+ * 5. the object constructed for the given DD-MM-YYYY HH:MM:SS corresponds to
+ * this moment in local time and may be converted to the object
+ * corresponding to the same date/time in another time zone by using
+ * ToTimezone()
+ *
+ * 6. the conversions to the current (or any other) timezone are done when the
+ * internal time representation is converted to the broken-down one in
+ * wxDateTime::Tm.
+ */
// ============================================================================
// declarations
#include "wx/log.h"
#endif // WX_PRECOMP
+#include "wx/thread.h"
+
#define wxDEFINE_TIME_CONSTANTS
#include "wx/datetime.h"
+#ifndef WX_TIMEZONE
+ #define WX_TIMEZONE timezone
+#endif
+
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
-// the number of days in month in Julian/Gregorian calendar: the first line is
-// for normal years, the second one is for the leap ones
-static wxDateTime::wxDateTime_t gs_daysInMonth[2][12] =
-{
- { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
- { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
-};
+// some trivial ones
+static const int MONTHS_IN_YEAR = 12;
+
+static const int SECONDS_IN_MINUTE = 60;
+
+static const long SECONDS_PER_DAY = 86400l;
+
+static const long MILLISECONDS_PER_DAY = 86400000l;
+
+// this is the integral part of JDN of the midnight of Jan 1, 1970
+// (i.e. JDN(Jan 1, 1970) = 2440587.5)
+static const int EPOCH_JDN = 2440587;
+
+// the date of JDN -0.5 (as we don't work with fractional parts, this is the
+// reference date for us) is Nov 24, 4714BC
+static const int JDN_0_YEAR = -4713;
+static const int JDN_0_MONTH = wxDateTime::Nov;
+static const int JDN_0_DAY = 24;
+
+// the constants used for JDN calculations
+static const int JDN_OFFSET = 32046;
+static const int DAYS_PER_5_MONTHS = 153;
+static const int DAYS_PER_4_YEARS = 1461;
+static const int DAYS_PER_400_YEARS = 146097;
+
+// ----------------------------------------------------------------------------
+// globals
+// ----------------------------------------------------------------------------
+
+// a critical section is needed to protect GetTimeZone() static
+// variable in MT case
+#ifdef wxUSE_THREADS
+ wxCriticalSection gs_critsectTimezone;
+#endif // wxUSE_THREADS
// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------
+// get the number of days in the given month of the given year
+static inline
+wxDateTime::wxDateTime_t GetNumOfDaysInMonth(int year, wxDateTime::Month month)
+{
+ // the number of days in month in Julian/Gregorian calendar: the first line
+ // is for normal years, the second one is for the leap ones
+ static wxDateTime::wxDateTime_t daysInMonth[2][MONTHS_IN_YEAR] =
+ {
+ { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+ { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+ };
+
+ return daysInMonth[wxDateTime::IsLeapYear(year)][month];
+}
+
+// ensure that the timezone variable is set by calling localtime
+static int GetTimeZone()
+{
+ // set to TRUE when the timezone is set
+ static bool s_timezoneSet = FALSE;
+
+ wxCRIT_SECT_LOCKER(lock, gs_critsectTimezone);
+
+ if ( !s_timezoneSet )
+ {
+ // just call localtime() instead of figuring out whether this system
+ // supports tzset(), _tzset() or something else
+ time_t t;
+ (void)localtime(&t);
+
+ s_timezoneSet = TRUE;
+ }
+
+ return (int)WX_TIMEZONE;
+}
+
+// return the integral part of the JDN for the midnight of the given date (to
+// get the real JDN you need to add 0.5, this is, in fact, JDN of the
+// noon of the previous day)
+static long GetTruncatedJDN(wxDateTime::wxDateTime_t day,
+ wxDateTime::Month mon,
+ int year)
+{
+ // CREDIT: code below is by Scott E. Lee (but bugs are mine)
+
+ // check the date validity
+ wxASSERT_MSG(
+ (year > JDN_0_YEAR) ||
+ ((year == JDN_0_YEAR) && (mon > JDN_0_MONTH)) ||
+ ((year == JDN_0_YEAR) && (mon == JDN_0_MONTH) && (day >= JDN_0_DAY)),
+ _T("date out of range - can't convert to JDN")
+ );
+
+ // make the year positive to avoid problems with negative numbers division
+ year += 4800;
+
+ // months are counted from March here
+ int month;
+ if ( mon >= wxDateTime::Mar )
+ {
+ month = mon - 2;
+ }
+ else
+ {
+ month = mon + 10;
+ year--;
+ }
+
+ // now we can simply add all the contributions together
+ return ((year / 100) * DAYS_PER_400_YEARS) / 4
+ + ((year % 100) * DAYS_PER_4_YEARS) / 4
+ + (month * DAYS_PER_5_MONTHS + 2) / 5
+ + day
+ - JDN_OFFSET;
+}
+
+// this function is a wrapper around strftime(3)
static wxString CallStrftime(const wxChar *format, const tm* tm)
{
wxChar buf[1024];
return wxString(buf);
}
+// if year and/or month have invalid values, replace them with the current ones
+static void ReplaceDefaultYearMonthWithCurrent(int *year,
+ wxDateTime::Month *month)
+{
+ struct tm *tmNow = NULL;
+
+ if ( *year == wxDateTime::Inv_Year )
+ {
+ tmNow = wxDateTime::GetTmNow();
+
+ *year = 1900 + tmNow->tm_year;
+ }
+
+ if ( *month == wxDateTime::Inv_Month )
+ {
+ if ( !tmNow )
+ tmNow = wxDateTime::GetTmNow();
+
+ *month = (wxDateTime::Month)tmNow->tm_mon;
+ }
+}
+
// ============================================================================
// implementation of wxDateTime
// ============================================================================
year = (wxDateTime_t)wxDateTime::Inv_Year;
mon = wxDateTime::Inv_Month;
mday = 0;
- hour = min = sec = 0;
+ hour = min = sec = msec = 0;
wday = wxDateTime::Inv_WeekDay;
}
-wxDateTime::Tm::Tm(const struct tm& tm)
+wxDateTime::Tm::Tm(const struct tm& tm, const TimeZone& tz)
+ : m_tz(tz)
{
+ msec = 0;
sec = tm.tm_sec;
min = tm.tm_min;
hour = tm.tm_hour;
mday = tm.tm_mday;
- mon = tm.tm_mon;
+ mon = (wxDateTime::Month)tm.tm_mon;
year = 1900 + tm.tm_year;
wday = tm.tm_wday;
yday = tm.tm_yday;
bool wxDateTime::Tm::IsValid() const
{
// we allow for the leap seconds, although we don't use them (yet)
- return (year != wxDateTime::Inv_Year) && (mon < 12) &&
- (mday < gs_daysInMonth[IsLeapYear(year)][mon]) &&
- (hour < 24) && (min < 60) && (sec < 62);
+ return (year != wxDateTime::Inv_Year) && (mon != wxDateTime::Inv_Month) &&
+ (mday <= GetNumOfDaysInMonth(year, mon)) &&
+ (hour < 24) && (min < 60) && (sec < 62) && (msec < 1000);
}
void wxDateTime::Tm::ComputeWeekDay()
{
- wxFAIL_MSG(_T("TODO"));
+ // compute the week day from day/month/year: we use the dumbest algorithm
+ // possible: just compute our JDN and then use the (simple to derive)
+ // formula: weekday = (JDN + 1.5) % 7
+ wday = (wxDateTime::WeekDay)(GetTruncatedJDN(mday, mon, year) + 2) % 7;
+}
+
+void wxDateTime::Tm::AddMonths(int monDiff)
+{
+ // normalize the months field
+ while ( monDiff < -mon )
+ {
+ year--;
+
+ monDiff += MONTHS_IN_YEAR;
+ }
+
+ while ( monDiff + mon > MONTHS_IN_YEAR )
+ {
+ year++;
+
+ monDiff -= MONTHS_IN_YEAR;
+ }
+
+ mon = (wxDateTime::Month)(mon + monDiff);
+
+ wxASSERT_MSG( mon >= 0 && mon < MONTHS_IN_YEAR, _T("logic error") );
+}
+
+void wxDateTime::Tm::AddDays(int dayDiff)
+{
+ // normalize the days field
+ mday += dayDiff;
+ while ( mday < 1 )
+ {
+ AddMonths(-1);
+
+ mday += GetNumOfDaysInMonth(year, mon);
+ }
+
+ while ( mday > GetNumOfDaysInMonth(year, mon) )
+ {
+ mday -= GetNumOfDaysInMonth(year, mon);
+
+ AddMonths(1);
+ }
+
+ wxASSERT_MSG( mday > 0 && mday <= GetNumOfDaysInMonth(year, mon),
+ _T("logic error") );
+}
+
+// ----------------------------------------------------------------------------
+// class TimeZone
+// ----------------------------------------------------------------------------
+
+wxDateTime::TimeZone::TimeZone(wxDateTime::TZ tz)
+{
+ switch ( tz )
+ {
+ case wxDateTime::Local:
+ // get the offset from C RTL: it returns the difference GMT-local
+ // while we want to have the offset _from_ GMT, hence the '-'
+ m_offset = -GetTimeZone();
+ break;
+
+ case wxDateTime::GMT_12:
+ case wxDateTime::GMT_11:
+ case wxDateTime::GMT_10:
+ case wxDateTime::GMT_9:
+ case wxDateTime::GMT_8:
+ case wxDateTime::GMT_7:
+ case wxDateTime::GMT_6:
+ case wxDateTime::GMT_5:
+ case wxDateTime::GMT_4:
+ case wxDateTime::GMT_3:
+ case wxDateTime::GMT_2:
+ case wxDateTime::GMT_1:
+ m_offset = -3600*(wxDateTime::GMT0 - tz);
+ break;
+
+ case wxDateTime::GMT0:
+ case wxDateTime::GMT1:
+ case wxDateTime::GMT2:
+ case wxDateTime::GMT3:
+ case wxDateTime::GMT4:
+ case wxDateTime::GMT5:
+ case wxDateTime::GMT6:
+ case wxDateTime::GMT7:
+ case wxDateTime::GMT8:
+ case wxDateTime::GMT9:
+ case wxDateTime::GMT10:
+ case wxDateTime::GMT11:
+ case wxDateTime::GMT12:
+ m_offset = 3600*(tz - wxDateTime::GMT0);
+ break;
+
+ case wxDateTime::A_CST:
+ // Central Standard Time in use in Australia = UTC + 9.5
+ m_offset = 60*(9*60 + 30);
+ break;
+
+ default:
+ wxFAIL_MSG( _T("unknown time zone") );
+ }
}
// ----------------------------------------------------------------------------
/* static */
bool wxDateTime::IsLeapYear(int year, wxDateTime::Calendar cal)
{
+ if ( year == Inv_Year )
+ year = GetCurrentYear();
+
if ( cal == Gregorian )
{
// in Gregorian calendar leap years are those divisible by 4 except
}
/* static */
-void wxDateTime::SetCountry(wxDateTime::Country country)
+int wxDateTime::GetCentury(int year)
{
- ms_country = country;
+ return year > 0 ? year / 100 : year / 100 - 1;
}
/* static */
return Inv_Month;
}
+/* static */
+wxDateTime::wxDateTime_t wxDateTime::GetNumberOfDays(int year, Calendar cal)
+{
+ if ( year == Inv_Year )
+ {
+ // take the current year if none given
+ year = GetCurrentYear();
+ }
+
+ switch ( cal )
+ {
+ case Gregorian:
+ case Julian:
+ return IsLeapYear(year) ? 366 : 365;
+ break;
+
+ default:
+ wxFAIL_MSG(_T("unsupported calendar"));
+ break;
+ }
+
+ return 0;
+}
+
/* static */
wxDateTime::wxDateTime_t wxDateTime::GetNumberOfDays(wxDateTime::Month month,
int year,
wxDateTime::Calendar cal)
{
- wxCHECK_MSG( month < 12, 0, _T("invalid month") );
+ wxCHECK_MSG( month < MONTHS_IN_YEAR, 0, _T("invalid month") );
if ( cal == Gregorian || cal == Julian )
{
year = GetCurrentYear();
}
- return gs_daysInMonth[IsLeapYear(year)][month];
+ return GetNumOfDaysInMonth(year, month);
}
else
{
// take some arbitrary Sunday
tm tm = { 0, 0, 0, 28, Nov, 99 };
- // and offset it by the number of days needed to get
+ // and offset it by the number of days needed to get the correct wday
tm.tm_mday += wday;
+ // call mktime() to normalize it...
+ (void)mktime(&tm);
+
+ // ... and call strftime()
return CallStrftime(abbr ? _T("%a") : _T("%A"), &tm);
}
+// ----------------------------------------------------------------------------
+// Country stuff: date calculations depend on the country (DST, work days,
+// ...), so we need to know which rules to follow.
+// ----------------------------------------------------------------------------
+
+/* static */
+wxDateTime::Country wxDateTime::GetCountry()
+{
+ if ( ms_country == Country_Unknown )
+ {
+ // try to guess from the time zone name
+ time_t t = time(NULL);
+ struct tm *tm = localtime(&t);
+
+ wxString tz = CallStrftime(_T("%Z"), tm);
+ if ( tz == _T("WET") || tz == _T("WEST") )
+ {
+ ms_country = UK;
+ }
+ else if ( tz == _T("CET") || tz == _T("CEST") )
+ {
+ ms_country = Country_EEC;
+ }
+ else if ( tz == _T("MSK") || tz == _T("MSD") )
+ {
+ ms_country = Russia;
+ }
+ else if ( tz == _T("AST") || tz == _T("ADT") ||
+ tz == _T("EST") || tz == _T("EDT") ||
+ tz == _T("CST") || tz == _T("CDT") ||
+ tz == _T("MST") || tz == _T("MDT") ||
+ tz == _T("PST") || tz == _T("PDT") )
+ {
+ ms_country = USA;
+ }
+ else
+ {
+ // well, choose a default one
+ ms_country = USA;
+ }
+ }
+
+ return ms_country;
+}
+
+/* static */
+void wxDateTime::SetCountry(wxDateTime::Country country)
+{
+ ms_country = country;
+}
+
+/* static */
+bool wxDateTime::IsWestEuropeanCountry(Country country)
+{
+ if ( country == Country_Default )
+ {
+ country = GetCountry();
+ }
+
+ return (Country_WesternEurope_Start <= country) &&
+ (country <= Country_WesternEurope_End);
+}
+
+// ----------------------------------------------------------------------------
+// DST calculations: we use 3 different rules for the West European countries,
+// USA and for the rest of the world. This is undoubtedly false for many
+// countries, but I lack the necessary info (and the time to gather it),
+// please add the other rules here!
+// ----------------------------------------------------------------------------
+
+/* static */
+bool wxDateTime::IsDSTApplicable(int year, Country country)
+{
+ if ( year == Inv_Year )
+ {
+ // take the current year if none given
+ year = GetCurrentYear();
+ }
+
+ if ( country == Country_Default )
+ {
+ country = GetCountry();
+ }
+
+ switch ( country )
+ {
+ case USA:
+ case UK:
+ // DST was first observed in the US and UK during WWI, reused
+ // during WWII and used again since 1966
+ return year >= 1966 ||
+ (year >= 1942 && year <= 1945) ||
+ (year == 1918 || year == 1919);
+
+ default:
+ // assume that it started after WWII
+ return year > 1950;
+ }
+}
+
+/* static */
+wxDateTime wxDateTime::GetBeginDST(int year, Country country)
+{
+ if ( year == Inv_Year )
+ {
+ // take the current year if none given
+ year = GetCurrentYear();
+ }
+
+ if ( country == Country_Default )
+ {
+ country = GetCountry();
+ }
+
+ if ( !IsDSTApplicable(year, country) )
+ {
+ return ms_InvDateTime;
+ }
+
+ wxDateTime dt;
+
+ if ( IsWestEuropeanCountry(country) || (country == Russia) )
+ {
+ // DST begins at 1 a.m. GMT on the last Sunday of March
+ if ( !dt.SetToLastWeekDay(Sun, Mar, year) )
+ {
+ // weird...
+ wxFAIL_MSG( _T("no last Sunday in March?") );
+ }
+
+ dt += wxTimeSpan::Hours(1);
+
+ dt.MakeGMT();
+ }
+ else switch ( country )
+ {
+ case USA:
+ switch ( year )
+ {
+ case 1918:
+ case 1919:
+ // don't know for sure - assume it was in effect all year
+
+ case 1943:
+ case 1944:
+ case 1945:
+ dt.Set(1, Jan, year);
+ break;
+
+ case 1942:
+ // DST was installed Feb 2, 1942 by the Congress
+ dt.Set(2, Feb, year);
+ break;
+
+ // Oil embargo changed the DST period in the US
+ case 1974:
+ dt.Set(6, Jan, 1974);
+ break;
+
+ case 1975:
+ dt.Set(23, Feb, 1975);
+ break;
+
+ default:
+ // before 1986, DST begun on the last Sunday of April, but
+ // in 1986 Reagan changed it to begin at 2 a.m. of the
+ // first Sunday in April
+ if ( year < 1986 )
+ {
+ if ( !dt.SetToLastWeekDay(Sun, Apr, year) )
+ {
+ // weird...
+ wxFAIL_MSG( _T("no first Sunday in April?") );
+ }
+ }
+ else
+ {
+ if ( !dt.SetToWeekDay(Sun, 1, Apr, year) )
+ {
+ // weird...
+ wxFAIL_MSG( _T("no first Sunday in April?") );
+ }
+ }
+
+ dt += wxTimeSpan::Hours(2);
+
+ // TODO what about timezone??
+ }
+
+ break;
+
+ default:
+ // assume Mar 30 as the start of the DST for the rest of the world
+ // - totally bogus, of course
+ dt.Set(30, Mar, year);
+ }
+
+ return dt;
+}
+
+/* static */
+wxDateTime wxDateTime::GetEndDST(int year, Country country)
+{
+ if ( year == Inv_Year )
+ {
+ // take the current year if none given
+ year = GetCurrentYear();
+ }
+
+ if ( country == Country_Default )
+ {
+ country = GetCountry();
+ }
+
+ if ( !IsDSTApplicable(year, country) )
+ {
+ return ms_InvDateTime;
+ }
+
+ wxDateTime dt;
+
+ if ( IsWestEuropeanCountry(country) || (country == Russia) )
+ {
+ // DST ends at 1 a.m. GMT on the last Sunday of October
+ if ( !dt.SetToLastWeekDay(Sun, Oct, year) )
+ {
+ // weirder and weirder...
+ wxFAIL_MSG( _T("no last Sunday in October?") );
+ }
+
+ dt += wxTimeSpan::Hours(1);
+
+ dt.MakeGMT();
+ }
+ else switch ( country )
+ {
+ case USA:
+ switch ( year )
+ {
+ case 1918:
+ case 1919:
+ // don't know for sure - assume it was in effect all year
+
+ case 1943:
+ case 1944:
+ dt.Set(31, Dec, year);
+ break;
+
+ case 1945:
+ // the time was reset after the end of the WWII
+ dt.Set(30, Sep, year);
+ break;
+
+ default:
+ // DST ends at 2 a.m. on the last Sunday of October
+ if ( !dt.SetToLastWeekDay(Sun, Oct, year) )
+ {
+ // weirder and weirder...
+ wxFAIL_MSG( _T("no last Sunday in October?") );
+ }
+
+ dt += wxTimeSpan::Hours(2);
+
+ // TODO what about timezone??
+ }
+ break;
+
+ default:
+ // assume October 26th as the end of the DST - totally bogus too
+ dt.Set(26, Oct, year);
+ }
+
+ return dt;
+}
+
// ----------------------------------------------------------------------------
// constructors and assignment operators
// ----------------------------------------------------------------------------
-wxDateTime& wxDateTime::Set(const struct tm& tm1)
+// the values in the tm structure contain the local time
+wxDateTime& wxDateTime::Set(const struct tm& tm)
{
wxASSERT_MSG( IsValid(), _T("invalid wxDateTime") );
- tm tm2(tm1);
+ struct tm tm2(tm);
time_t timet = mktime(&tm2);
- if ( timet == (time_t)(-1) )
+
+ if ( timet == (time_t)-1 )
{
- wxFAIL_MSG(_T("Invalid time"));
+ // mktime() rather unintuitively fails for Jan 1, 1970 if the hour is
+ // less than timezone - try to make it work for this case
+ if ( tm2.tm_year == 70 && tm2.tm_mon == 0 && tm2.tm_mday == 1 )
+ {
+ // add timezone to make sure that date is in range
+ tm2.tm_sec -= GetTimeZone();
+
+ timet = mktime(&tm2);
+ if ( timet != (time_t)-1 )
+ {
+ timet += GetTimeZone();
+
+ return Set(timet);
+ }
+ }
+
+ wxFAIL_MSG( _T("mktime() failed") );
return ms_InvDateTime;
}
time_t timet = GetTimeNow();
struct tm *tm = localtime(&timet);
+ wxCHECK_MSG( tm, ms_InvDateTime, _T("localtime() failed") );
+
// adjust the time
tm->tm_hour = hour;
tm->tm_min = minute;
ms_InvDateTime,
_T("Invalid time in wxDateTime::Set()") );
- if ( year == Inv_Year )
- year = GetCurrentYear();
- if ( month == Inv_Month )
- month = GetCurrentMonth();
+ ReplaceDefaultYearMonthWithCurrent(&year, &month);
- wxCHECK_MSG( day < GetNumberOfDays(month, year), ms_InvDateTime,
+ wxCHECK_MSG( (0 < day) && (day <= GetNumberOfDays(month, year)),
+ ms_InvDateTime,
_T("Invalid date in wxDateTime::Set()") );
// the range of time_t type (inclusive)
// test only the year instead of testing for the exact end of the Unix
// time_t range - it doesn't bring anything to do more precise checks
- if ( year >= yearMaxInRange && year <= yearMaxInRange )
+ if ( year >= yearMinInRange && year <= yearMaxInRange )
{
// use the standard library version if the date is in range - this is
// probably more efficient than our code
tm.tm_hour = hour;
tm.tm_min = minute;
tm.tm_sec = second;
+ tm.tm_isdst = -1; // mktime() will guess it
(void)Set(tm);
else
{
// do time calculations ourselves: we want to calculate the number of
- // milliseconds between the given date and the epoch (necessarily
- // negative)
- wxFAIL_MSG(_T("TODO"));
+ // milliseconds between the given date and the epoch
+
+ // get the JDN for the midnight of this day
+ m_time = GetTruncatedJDN(day, month, year);
+ m_time -= EPOCH_JDN;
+ m_time *= SECONDS_PER_DAY * TIME_T_FACTOR;
+
+ // JDN corresponds to GMT, we take localtime
+ Add(wxTimeSpan(hour, minute, second + GetTimeZone(), millisec));
}
return *this;
}
+wxDateTime& wxDateTime::Set(double jdn)
+{
+ // so that m_time will be 0 for the midnight of Jan 1, 1970 which is jdn
+ // EPOCH_JDN + 0.5
+ jdn -= EPOCH_JDN + 0.5;
+
+ m_time = jdn;
+ m_time *= MILLISECONDS_PER_DAY;
+
+ return *this;
+}
+
// ----------------------------------------------------------------------------
// time_t <-> broken down time conversions
// ----------------------------------------------------------------------------
-wxDateTime::Tm wxDateTime::GetTm() const
+wxDateTime::Tm wxDateTime::GetTm(const TimeZone& tz) const
{
wxASSERT_MSG( IsValid(), _T("invalid wxDateTime") );
if ( time != (time_t)-1 )
{
// use C RTL functions
- tm *tm = localtime(&time);
+ tm *tm;
+ if ( tz.GetOffset() == -GetTimeZone() )
+ {
+ // we are working with local time
+ tm = localtime(&time);
- // should never happen
- wxCHECK_MSG( tm, Tm(), _T("localtime() failed") );
+ // should never happen
+ wxCHECK_MSG( tm, Tm(), _T("gmtime() failed") );
+ }
+ else
+ {
+ time += tz.GetOffset();
+ if ( time >= 0 )
+ {
+ tm = gmtime(&time);
+
+ // should never happen
+ wxCHECK_MSG( tm, Tm(), _T("gmtime() failed") );
+ }
+ else
+ {
+ tm = (struct tm *)NULL;
+ }
+ }
- return Tm(*tm);
+ if ( tm )
+ {
+ return Tm(*tm, tz);
+ }
+ //else: use generic code below
}
- else
+
+ // remember the time and do the calculations with the date only - this
+ // eliminates rounding errors of the floating point arithmetics
+
+ wxLongLong timeMidnight = m_time + tz.GetOffset() * 1000;
+
+ long timeOnly = (timeMidnight % MILLISECONDS_PER_DAY).ToLong();
+
+ // we want to always have positive time and timeMidnight to be really
+ // the midnight before it
+ if ( timeOnly < 0 )
{
- wxFAIL_MSG(_T("TODO"));
+ timeOnly = MILLISECONDS_PER_DAY + timeOnly;
+ }
+
+ timeMidnight -= timeOnly;
+
+ // calculate the Gregorian date from JDN for the midnight of our date:
+ // this will yield day, month (in 1..12 range) and year
+
+ // actually, this is the JDN for the noon of the previous day
+ long jdn = (timeMidnight / MILLISECONDS_PER_DAY).ToLong() + EPOCH_JDN;
+
+ // CREDIT: code below is by Scott E. Lee (but bugs are mine)
- return Tm();
+ wxASSERT_MSG( jdn > -2, _T("JDN out of range") );
+
+ // calculate the century
+ int temp = (jdn + JDN_OFFSET) * 4 - 1;
+ int century = temp / DAYS_PER_400_YEARS;
+
+ // then the year and day of year (1 <= dayOfYear <= 366)
+ temp = ((temp % DAYS_PER_400_YEARS) / 4) * 4 + 3;
+ int year = (century * 100) + (temp / DAYS_PER_4_YEARS);
+ int dayOfYear = (temp % DAYS_PER_4_YEARS) / 4 + 1;
+
+ // and finally the month and day of the month
+ temp = dayOfYear * 5 - 3;
+ int month = temp / DAYS_PER_5_MONTHS;
+ int day = (temp % DAYS_PER_5_MONTHS) / 5 + 1;
+
+ // month is counted from March - convert to normal
+ if ( month < 10 )
+ {
+ month += 3;
}
+ else
+ {
+ year += 1;
+ month -= 9;
+ }
+
+ // year is offset by 4800
+ year -= 4800;
+
+ // check that the algorithm gave us something reasonable
+ wxASSERT_MSG( (0 < month) && (month <= 12), _T("invalid month") );
+ wxASSERT_MSG( (1 <= day) && (day < 32), _T("invalid day") );
+ wxASSERT_MSG( (INT_MIN <= year) && (year <= INT_MAX),
+ _T("year range overflow") );
+
+ // construct Tm from these values
+ Tm tm;
+ tm.year = (int)year;
+ tm.mon = (Month)(month - 1); // algorithm yields 1 for January, not 0
+ tm.mday = (wxDateTime_t)day;
+ tm.msec = timeOnly % 1000;
+ timeOnly -= tm.msec;
+ timeOnly /= 1000; // now we have time in seconds
+
+ tm.sec = timeOnly % 60;
+ timeOnly -= tm.sec;
+ timeOnly /= 60; // now we have time in minutes
+
+ tm.min = timeOnly % 60;
+ timeOnly -= tm.min;
+
+ tm.hour = timeOnly / 60;
+
+ return tm;
}
wxDateTime& wxDateTime::SetYear(int year)
Tm tm(GetTm());
tm.year += diff.GetYears();
- tm.mon += diff.GetMonths();
- tm.mday += diff.GetTotalDays();
+ tm.AddMonths(diff.GetMonths());
+ tm.AddDays(diff.GetTotalDays());
Set(tm);
return *this;
}
+// ----------------------------------------------------------------------------
+// Weekday and monthday stuff
+// ----------------------------------------------------------------------------
+
+wxDateTime& wxDateTime::SetToLastMonthDay(Month month,
+ int year)
+{
+ // take the current month/year if none specified
+ ReplaceDefaultYearMonthWithCurrent(&year, &month);
+
+ return Set(GetNumOfDaysInMonth(year, month), month, year);
+}
+
+bool wxDateTime::SetToWeekDay(WeekDay weekday,
+ int n,
+ Month month,
+ int year)
+{
+ wxCHECK_MSG( weekday != Inv_WeekDay, FALSE, _T("invalid weekday") );
+
+ // we don't check explicitly that -5 <= n <= 5 because we will return FALSE
+ // anyhow in such case - but may be should still give an assert for it?
+
+ // take the current month/year if none specified
+ ReplaceDefaultYearMonthWithCurrent(&year, &month);
+
+ wxDateTime dt;
+
+ // TODO this probably could be optimised somehow...
+
+ if ( n > 0 )
+ {
+ // get the first day of the month
+ dt.Set(1, month, year);
+
+ // get its wday
+ WeekDay wdayFirst = dt.GetWeekDay();
+
+ // go to the first weekday of the month
+ int diff = weekday - wdayFirst;
+ if ( diff < 0 )
+ diff += 7;
+
+ // add advance n-1 weeks more
+ diff += 7*(n - 1);
+
+ dt += wxDateSpan::Days(diff);
+ }
+ else // count from the end of the month
+ {
+ // get the last day of the month
+ dt.SetToLastMonthDay(month, year);
+
+ // get its wday
+ WeekDay wdayLast = dt.GetWeekDay();
+
+ // go to the last weekday of the month
+ int diff = wdayLast - weekday;
+ if ( diff < 0 )
+ diff += 7;
+
+ // and rewind n-1 weeks from there
+ diff += 7*(-n - 1);
+
+ dt -= wxDateSpan::Days(diff);
+ }
+
+ // check that it is still in the same month
+ if ( dt.GetMonth() == month )
+ {
+ *this = dt;
+
+ return TRUE;
+ }
+ else
+ {
+ // no such day in this month
+ return FALSE;
+ }
+}
+
+wxDateTime::wxDateTime_t wxDateTime::GetDayOfYear(const TimeZone& tz) const
+{
+ // this array contains the cumulated number of days in all previous months
+ // for normal and leap years
+ static const wxDateTime_t cumulatedDays[2][MONTHS_IN_YEAR] =
+ {
+ { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
+ { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 }
+ };
+
+ Tm tm(GetTm(tz));
+
+ return cumulatedDays[IsLeapYear(tm.year)][tm.mon] + tm.mday;
+}
+
+wxDateTime::wxDateTime_t wxDateTime::GetWeekOfYear(const TimeZone& tz) const
+{
+ // the first week of the year is the one which contains Jan, 4 (according
+ // to ISO standard rule), so the year day N0 = 4 + 7*W always lies in the
+ // week W+1. As any day N = 7*W + 4 + (N - 4)%7, it lies in the same week
+ // as N0 or in the next one.
+
+ // TODO this surely may be optimized - I got confused while writing it
+
+ wxDateTime_t nDayInYear = GetDayOfYear(tz);
+
+ // the week day of the day lying in the first week
+ WeekDay wdayStart = wxDateTime(4, Jan, GetYear()).GetWeekDay();
+
+ wxDateTime_t week = (nDayInYear - 4) / 7 + 1;
+
+ // notice that Sunday shoould be counted as 7, not 0 here!
+ if ( ((nDayInYear - 4) % 7) + (!wdayStart ? 7 : wdayStart) > 7 )
+ {
+ week++;
+ }
+
+ return week;
+}
+
+// ----------------------------------------------------------------------------
+// Julian day number conversion and related stuff
+// ----------------------------------------------------------------------------
+
+double wxDateTime::GetJulianDayNumber() const
+{
+ // JDN are always expressed for the GMT dates
+ Tm tm(ToTimezone(GMT0).GetTm(GMT0));
+
+ double result = GetTruncatedJDN(tm.mday, tm.mon, tm.year);
+
+ // add the part GetTruncatedJDN() neglected
+ result += 0.5;
+
+ // and now add the time: 86400 sec = 1 JDN
+ return result + ((double)(60*(60*tm.hour + tm.min) + tm.sec)) / 86400;
+}
+
+double wxDateTime::GetRataDie() const
+{
+ // March 1 of the year 0 is Rata Die day -306 and JDN 1721119.5
+ return GetJulianDayNumber() - 1721119.5 - 306;
+}
+
+// ----------------------------------------------------------------------------
+// timezone and DST stuff
+// ----------------------------------------------------------------------------
+
+int wxDateTime::IsDST(wxDateTime::Country country) const
+{
+ wxCHECK_MSG( country == Country_Default, -1,
+ _T("country support not implemented") );
+
+ // use the C RTL for the dates in the standard range
+ time_t timet = GetTicks();
+ if ( timet != (time_t)-1 )
+ {
+ tm *tm = localtime(&timet);
+
+ wxCHECK_MSG( tm, -1, _T("localtime() failed") );
+
+ return tm->tm_isdst;
+ }
+ else
+ {
+ int year = GetYear();
+
+ if ( !IsDSTApplicable(year, country) )
+ {
+ // no DST time in this year in this country
+ return -1;
+ }
+
+ return IsBetween(GetBeginDST(year, country), GetEndDST(year, country));
+ }
+}
+
+wxDateTime& wxDateTime::MakeTimezone(const TimeZone& tz)
+{
+ int secDiff = GetTimeZone() + tz.GetOffset();
+
+ // we need to know whether DST is or not in effect for this date
+ if ( IsDST() == 1 )
+ {
+ // FIXME we assume that the DST is always shifted by 1 hour
+ secDiff -= 3600;
+ }
+
+ return Substract(wxTimeSpan::Seconds(secDiff));
+}
+
// ----------------------------------------------------------------------------
// wxDateTime to/from text representations
// ----------------------------------------------------------------------------
-wxString wxDateTime::Format(const wxChar *format) const
+wxString wxDateTime::Format(const wxChar *format, const TimeZone& tz) const
{
+ wxCHECK_MSG( format, _T(""), _T("NULL format in wxDateTime::Format") );
+
time_t time = GetTicks();
if ( time != (time_t)-1 )
{
// use strftime()
- tm *tm = localtime(&time);
+ tm *tm;
+ if ( tz.GetOffset() == -GetTimeZone() )
+ {
+ // we are working with local time
+ tm = localtime(&time);
- // should never happen
- wxCHECK_MSG( tm, _T(""), _T("localtime() failed") );
+ // should never happen
+ wxCHECK_MSG( tm, wxEmptyString, _T("localtime() failed") );
+ }
+ else
+ {
+ time += tz.GetOffset();
+
+ if ( time >= 0 )
+ {
+ tm = gmtime(&time);
+
+ // should never happen
+ wxCHECK_MSG( tm, wxEmptyString, _T("gmtime() failed") );
+ }
+ else
+ {
+ tm = (struct tm *)NULL;
+ }
+ }
- return CallStrftime(format, tm);
+ if ( tm )
+ {
+ return CallStrftime(format, tm);
+ }
+ //else: use generic code below
}
- else
+
+ // use a hack and still use strftime(): first find the YEAR which is a year
+ // in the strftime() range (1970 - 2038) whose Jan 1 falls on the same week
+ // day as the Jan 1 of the real year. Then make a copy of the format and
+ // replace all occurences of YEAR in it with some unique string not
+ // appearing anywhere else in it, then use strftime() to format the date in
+ // year YEAR and then replace YEAR back by the real year and the unique
+ // replacement string back with YEAR. Notice that "all occurences of YEAR"
+ // means all occurences of 4 digit as well as 2 digit form!
+
+ // NB: may be it would be simpler to "honestly" reimplement strftime()?
+
+ // find the YEAR: normally, for any year X, Jan 1 or the year X + 28 is the
+ // same weekday as Jan 1 of X (because the weekday advances by 1 for each
+ // normal X and by 2 for each leap X, hence by 5 every 4 years or by 35
+ // which is 0 mod 7 every 28 years) but this rule breaks down if there are
+ // years between X and Y which are divisible by 4 but not leap (i.e.
+ // divisible by 100 but not 400), hence the correction.
+
+ int yearReal = GetYear(tz);
+ int year = 1970 + yearReal % 28;
+
+ int nCenturiesInBetween = (year / 100) - (yearReal / 100);
+ int nLostWeekDays = nCenturiesInBetween - (nCenturiesInBetween / 400);
+
+ // we have to gain back the "lost" weekdays...
+ while ( (nLostWeekDays % 7) != 0 )
+ {
+ nLostWeekDays += year++ % 4 ? 1 : 2;
+ }
+
+ // at any rate, we can't go further than 1997 + 28!
+ wxASSERT_MSG( year < 2030, _T("logic error in wxDateTime::Format") );
+
+ wxString strYear, strYear2;
+ strYear.Printf(_T("%d"), year);
+ strYear2.Printf(_T("%d"), year % 100);
+
+ // find two strings not occuring in format (this is surely not optimal way
+ // of doing it... improvements welcome!)
+ wxString fmt = format;
+ wxString replacement = (wxChar)-1;
+ while ( fmt.Find(replacement) != wxNOT_FOUND )
{
- wxFAIL_MSG(_T("TODO"));
+ replacement << (wxChar)-1;
+ }
- return _T("");
+ wxString replacement2 = (wxChar)-2;
+ while ( fmt.Find(replacement) != wxNOT_FOUND )
+ {
+ replacement << (wxChar)-2;
}
+
+ // replace all occurences of year with it
+ bool wasReplaced = fmt.Replace(strYear, replacement) > 0;
+ if ( !wasReplaced )
+ wasReplaced = fmt.Replace(strYear2, replacement2) > 0;
+
+ // use strftime() to format the same date but in supported year
+ wxDateTime dt(*this);
+ dt.SetYear(year);
+ wxString str = dt.Format(format, tz);
+
+ // now replace the occurence of 1999 with the real year
+ wxString strYearReal, strYearReal2;
+ strYearReal.Printf(_T("%04d"), yearReal);
+ strYearReal2.Printf(_T("%02d"), yearReal % 100);
+ str.Replace(strYear, strYearReal);
+ str.Replace(strYear2, strYearReal2);
+
+ // and replace back all occurences of replacement string
+ if ( wasReplaced )
+ {
+ str.Replace(replacement2, strYear2);
+ str.Replace(replacement, strYear);
+ }
+
+ return str;
+}
+
+// ============================================================================
+// wxTimeSpan
+// ============================================================================
+
+// not all strftime(3) format specifiers make sense here because, for example,
+// a time span doesn't have a year nor a timezone
+//
+// Here are the ones which are supported (all of them are supported by strftime
+// as well):
+// %H hour in 24 hour format
+// %M minute (00 - 59)
+// %S second (00 - 59)
+// %% percent sign
+//
+// Also, for MFC CTimeSpan compatibility, we support
+// %D number of days
+//
+// And, to be better than MFC :-), we also have
+// %E number of wEeks
+// %l milliseconds (000 - 999)
+wxString wxTimeSpan::Format(const wxChar *format) const
+{
+ wxCHECK_MSG( format, _T(""), _T("NULL format in wxTimeSpan::Format") );
+
+ wxString str;
+ str.Alloc(strlen(format));
+
+ for ( const wxChar *pch = format; pch; pch++ )
+ {
+ wxChar ch = *pch;
+
+ if ( ch == '%' )
+ {
+ wxString tmp;
+
+ ch = *pch++;
+ switch ( ch )
+ {
+ default:
+ wxFAIL_MSG( _T("invalid format character") );
+ // fall through
+
+ case '%':
+ // will get to str << ch below
+ break;
+
+ case 'D':
+ tmp.Printf(_T("%d"), GetDays());
+ break;
+
+ case 'E':
+ tmp.Printf(_T("%d"), GetWeeks());
+ break;
+
+ case 'H':
+ tmp.Printf(_T("%02d"), GetHours());
+ break;
+
+ case 'l':
+ tmp.Printf(_T("%03d"), GetMilliseconds().GetValue());
+ break;
+
+ case 'M':
+ tmp.Printf(_T("%02d"), GetMinutes());
+ break;
+
+ case 'S':
+ tmp.Printf(_T("%02d"), GetSeconds().GetValue());
+ break;
+ }
+
+ if ( !!tmp )
+ {
+ str += tmp;
+
+ // skip str += ch below
+ continue;
+ }
+ }
+
+ str += ch;
+ }
+
+ return str;
}
projects / wxWidgets.git / blobdiff