public static TimeZoneInfo ToSystemTimeZone(this PosixTz posixTz, int year, bool isDaylightSavingTime = true)
{
if ((object)posixTz == null)
{
return(null);
}
var id = posixTz.name;
if (id.Length > 32)
{
id = id.Substring(0, 32);
}
var baseOffset = TimeSpan.FromSeconds(-posixTz.offset);
if ((object)posixTz.dst == null || !isDaylightSavingTime)
{
return(TimeZoneInfo.CreateCustomTimeZone(
id, baseOffset, posixTz.Format(), posixTz.name
));
}
var daylightDelta = TimeSpan.FromSeconds(
posixTz.offset - posixTz.dst.offset
);
var start = posixTz.dst.start.ToSystemTransitionTime(year);
var end = posixTz.dst.end.ToSystemTransitionTime(year);
var adjustmentRule = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(
new DateTime(year, 1, 1), new DateTime(year, 12, 31), daylightDelta, start, end
);
return(TimeZoneInfo.CreateCustomTimeZone(
id, baseOffset, posixTz.Format(), posixTz.name, posixTz.dst.name, new[] { adjustmentRule }
));
}
