// Author: Vadim Zeitlin
// Modified by:
// Created: 11.05.99
-// RCS-ID: $Id$
// Copyright: (c) 1999 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// parts of code taken from sndcal library by Scott E. Lee:
//
return *this;
}
- else
- {
- return Set(timet);
+
+ // mktime() only adjusts tm_wday, tm_yday and tm_isdst fields normally, if
+ // it changed anything else, it must have performed the DST adjustment. But
+ // the trouble with this is that different implementations do it
+ // differently, e.g. GNU libc moves the time forward if the specified time
+ // is invalid in the local time zone, while MSVC CRT moves it backwards
+ // which is especially pernicious as it can change the date if the DST
+ // starts at midnight, as it does in some time zones (see #15419), and this
+ // is completely unexpected for the code working with dates only.
+ //
+ // So standardize on moving the time forwards to have consistent behaviour
+ // under all platforms and to avoid the problem above.
+ if ( tm2.tm_hour != tm.tm_hour )
+ {
+ tm2 = tm;
+ tm2.tm_hour++;
+ if ( tm2.tm_hour == 24 )
+ {
+ // This shouldn't normally happen as the DST never starts at 23:00
+ // but if it does, we have a problem as we need to adjust the day
+ // as well. However we stop here, i.e. we don't adjust the month
+ // (or the year) because mktime() is supposed to take care of this
+ // for us.
+ tm2.tm_hour = 0;
+ tm2.tm_mday++;
+ }
+
+ timet = mktime(&tm2);
}
+
+ return Set(timet);
}
wxDateTime& wxDateTime::Set(wxDateTime_t hour,
return *this;
}
+wxDateSpan wxDateTime::DiffAsDateSpan(const wxDateTime& dt) const
+{
+ wxASSERT_MSG( IsValid() && dt.IsValid(), wxT("invalid wxDateTime"));
+
+ // If dt is larger than this, calculations below needs to be inverted.
+ int inv = 1;
+ if ( dt > *this )
+ inv = -1;
+
+ int y = GetYear() - dt.GetYear();
+ int m = GetMonth() - dt.GetMonth();
+ int d = GetDay() - dt.GetDay();
+
+ // If month diff is negative, dt is the year before, so decrease year
+ // and set month diff to its inverse, e.g. January - December should be 1,
+ // not -11.
+ if ( m * inv < 0 || (m == 0 && d * inv < 0))
+ {
+ m += inv * MONTHS_IN_YEAR;
+ y -= inv;
+ }
+
+ // Same logic for days as for months above.
+ if ( d * inv < 0 )
+ {
+ // Use number of days in month from the month which end date we're
+ // crossing. That is month before this for positive diff, and this
+ // month for negative diff.
+ // If we're on january and using previous month, we get december
+ // previous year, but don't care, december has same amount of days
+ // every year.
+ wxDateTime::Month monthfordays = GetMonth();
+ if (inv > 0 && monthfordays == wxDateTime::Jan)
+ monthfordays = wxDateTime::Dec;
+ else if (inv > 0)
+ monthfordays = static_cast<wxDateTime::Month>(monthfordays - 1);
+
+ d += inv * wxDateTime::GetNumberOfDays(monthfordays, GetYear());
+ m -= inv;
+ }
+
+ int w = d / DAYS_PER_WEEK;
+
+ // Remove weeks from d, since wxDateSpan only keep days as the ones
+ // not in complete weeks
+ d -= w * DAYS_PER_WEEK;
+
+ return wxDateSpan(y, m, w, d);
+}
+
// ----------------------------------------------------------------------------
// Weekday and monthday stuff
// ----------------------------------------------------------------------------
{
// adjust the weekdays to non-US style.
wdYearStart = ConvertWeekDayToMondayBase(wdYearStart);
- wdTarget = ConvertWeekDayToMondayBase(wdTarget);
// quoting from http://www.cl.cam.ac.uk/~mgk25/iso-time.html:
//
//
// if Jan 1 is Thursday or less, it is in the first week of this year
- if ( wdYearStart < 4 )
- {
- // count the number of entire weeks between Jan 1 and this date
- week = (nDayInYear + wdYearStart + 6 - wdTarget)/7;
+ int dayCountFix = wdYearStart < 4 ? 6 : -1;
+
+ // count the number of week
+ week = (nDayInYear + wdYearStart + dayCountFix) / DAYS_PER_WEEK;
- // be careful to check for overflow in the next year
- if ( week == 53 && tm.mday - wdTarget > 28 )
- week = 1;
+ // check if we happen to be at the last week of previous year:
+ if ( week == 0 )
+ {
+ week = wxDateTime(31, Dec, GetYear() - 1).GetWeekOfYear();
}
- else // Jan 1 is in the last week of the previous year
+ else if ( week == 53 )
{
- // check if we happen to be at the last week of previous year:
- if ( tm.mon == Jan && tm.mday < 8 - wdYearStart )
- week = wxDateTime(31, Dec, GetYear()-1).GetWeekOfYear();
- else
- week = (nDayInYear + wdYearStart - 1 - wdTarget)/7;
+ int wdYearEnd = (wdYearStart + 364 + IsLeapYear(GetYear()))
+ % DAYS_PER_WEEK;
+
+ // Week 53 only if last day of year is Thursday or later.
+ if ( wdYearEnd < 3 )
+ week = 1;
}
}
projects / wxWidgets.git / blobdiff