public static TimeZoneInfo.AdjustmentRule GetStaticAdjustmentRule(RegistryTimeZoneInformation information)
{
if (RegistryTimeZoneUtils.IsDaylightSavingsEnabled())
{
return(CreateStaticAdjustmentRule(information.Bias, information.StandardBias, information.DaylightBias, information.StandardDate, information.DaylightDate));
}
else
{
// We cant have an AdjustmentRule if there is no DST
return(null);
}
}
/// <summary>
/// This will return the static timezone adjustment rule the the OS uses.
/// We assume that the static rule is used by one of the dynamic adjustment rules.
/// </summary>
public static TimeZoneInfo.AdjustmentRule FindSystemStaticAdjustmentRule(string keyName)
{
RegistryTimeZoneInformation information = RegistryTimeZoneUtils.GetStaticTimeZoneInformation(keyName);
if (information == null)
{
throw new TimeZoneNotFoundException();
}
else
{
return(GetStaticAdjustmentRule(information));
}
}
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 }));
}
}