// Get the daylight saving time rules for this timezone in a given year.
public override DaylightTime GetDaylightChanges(int year)
{
long start, end, delta;
if (year < 1 || year > 9999)
{
throw new ArgumentOutOfRangeException
(_("ArgRange_Year"));
}
lock (this)
{
if (cachedYear == year)
{
return(cachedChanges);
}
if (TimeMethods.GetDaylightRules
(year, out start, out end, out delta))
{
cachedChanges = new DaylightTime
(new DateTime(start),
new DateTime(end),
new TimeSpan(delta));
}
else
{
cachedChanges = new DaylightTime
(DateTime.MinValue, DateTime.MaxValue,
TimeSpan.Zero);
}
cachedYear = year;
return(cachedChanges);
}
}
// Convert this DateTime value into UTC time.
public DateTime ToUniversalTime()
{
return(new DateTime
(value_ + ((long)(TimeMethods.GetTimeZoneAdjust(value_))) *
TimeSpan.TicksPerSecond));
}
// Get the offset from UTC of this timezone at a given time.
public override TimeSpan GetUtcOffset(DateTime time)
{
int secs = TimeMethods.GetTimeZoneAdjust(time.Ticks);
return(new TimeSpan(-secs * TimeSpan.TicksPerSecond));
}