On Tuesday 27 August 2013 10:19:06 Calogero Mauceri wrote: > On 8/26/2013 7:30 PM, Thiago Macieira wrote: > > On segunda-feira, 26 de agosto de 2013 17:42:58, Calogero Mauceri wrote: > >> QDateTime myDateTime = QDateTime::fromTime_t(f_mtime); > >> > >> The date time printed doing a myDateTime.toString() is > >> > >> Wed Dec 5 12:36:18 2007 > >> > >> Retrieving the last modified information using QFileInfo, the result is > >> different > >> > >> QFileInfo fi(filepath); > >> QDateTime myDateTime = fi.lastModified(); > >> > >> I get this result > >> > >> Wed Dec 5 11:36:18 2007 > >> > >> That is there is one hour difference. I guess the difference is due to > >> the daylight saving management, > >> but I can not understand how that management is performed. > >> > >> Note: if I look at the file properties on Windows dialog, the last > >> modified time is shown as > >> > >> Wed Dec 5 12:36:18 2007 > > > > Ah, Windows... > > > > The problem might be simply a matter of timezones. The timestamps on files > > on Windows are not stored with time_t, but with some Windows-specific > > data. We get a FILETIME back from Win32. > > > > Anyway, up until Qt 5.2, you cannot trust the output of a QDateTime with > > qDebug since it does not include the timezone. You have to ensure that the > > > > dates you're comparing by text are in the same timezone: > > qDebug() << dt.toUTC(); > > Thanks for your reply. > > Unfortunately the problem is still there even if I force a toUTC() > conversion for both QDateTime, either the one initialized from time_t or > the one returned by QFileInfo :/. > Similarly > > QDateTime dtFromTime_t = QDateTime::fromTime_t(mtime).toUTC(); > QDateTime dtFromFileInfo = fi.lastModified().toUTC(); > int sec = ABS(dtFromTime.secsTo(dtFromFileInfo)); // sec returned > is 3600
Daylight savings handling in windows is somehow 'weird'. The timestamps of files change when switching the system time from summer time to winter time and vice versa. Frank _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
