public static DateTime SetValidTimeOfDay(DateTime dateTime, TimeSpan timeOfDay, TimeZoneInfo timezone)
{
dateTime = DateTimeUtils.SetTimeOfDay(dateTime, timeOfDay);
// time can be invalid when setting the clock one hour forward
if (timezone.IsInvalidTime(dateTime))
{
TimeZoneInfo.AdjustmentRule rule = AdjustmentRuleUtils.GetAdjustmentRuleForTime(timezone.GetAdjustmentRules(), dateTime.Date);
// rule cannot be null for invalid time
dateTime = dateTime.Add(rule.DaylightDelta);
}
dateTime = DateTime.SpecifyKind(dateTime, DateTimeKind.Unspecified);
return(dateTime);
}
public static DateTime SafeConvertToUtc(DateTime dateTime, TimeZoneInfo sourceTimeZone)
{
// time can be invalid when setting the clock one hour forward
if (sourceTimeZone.IsInvalidTime(dateTime))
{
TimeZoneInfo.AdjustmentRule rule = AdjustmentRuleUtils.GetAdjustmentRuleForTime(sourceTimeZone.GetAdjustmentRules(), dateTime.Date);
// rule cannot be null for invalid time
return(TimeZoneInfo.ConvertTimeToUtc(dateTime.Add(rule.DaylightDelta), sourceTimeZone));
}
else
{
return(TimeZoneInfo.ConvertTimeToUtc(dateTime, sourceTimeZone));
}
}
public static DateTime AdvancedConvertToUtc(DateTime dateTime, TimeZoneInfo sourceTimeZone, bool assumeDaylightTimeForAmbiguousTime)
{
DateTime result = SafeConvertToUtc(dateTime, sourceTimeZone);
// time can be ambiguous when setting the clock one hour backward
if (sourceTimeZone.IsAmbiguousTime(dateTime) && assumeDaylightTimeForAmbiguousTime)
{
TimeZoneInfo.AdjustmentRule rule = AdjustmentRuleUtils.GetAdjustmentRuleForTime(sourceTimeZone.GetAdjustmentRules(), dateTime.Date);
// ConvertTimeToUtc will assume standard time, we want it to assume daylight time
// rule cannot be null for ambiguous time
result = result.Add(-rule.DaylightDelta);
}
return(result);
}
public static TimeZoneInfo GetSystemStaticTimeZone(string keyName)
{
RegistryTimeZoneInformation information = RegistryTimeZoneUtils.GetStaticTimeZoneInformation(keyName);
TimeZoneInfo.AdjustmentRule rule = AdjustmentRuleUtils.GetStaticAdjustmentRule(information);
string displayName;
string standardDisplayName;
string daylightDisplayName;
displayName = RegistryTimeZoneUtils.GetDisplayName(keyName, out standardDisplayName, out daylightDisplayName);
TimeSpan baseUtcOffset = new TimeSpan(0, -(information.Bias + information.StandardBias), 0);
if (rule == null)
{
// null will only be returned if there is no daylight saving
return(TimeZoneInfo.CreateCustomTimeZone(keyName, baseUtcOffset, displayName, standardDisplayName));
}
else
{
return(TimeZoneInfo.CreateCustomTimeZone(keyName, baseUtcOffset, displayName, standardDisplayName, daylightDisplayName, new TimeZoneInfo.AdjustmentRule[] { rule }));
}
}