Daylight Savings Notice

Our office does not observe Daylight Savings. I wanted to display a notice on our order form to make users aware when daylight savings was changing. After spending hours not finding a way, I found code here . I added a method to it adapted from his code. I just wanted the dates daylight saving start and ends for a given TimeZone. I had already tried:

DaylightTime daylight = TimeZone.CurrentTimeZone.GetDaylightChanges(DateTime.Today.Year);

But that only gives it for the time zone of the server. I needed to get a System.Globalization.DaylightTime for a timezone that observes Daylight Saving.

public static DaylightTime GetDaylightChanges(TimeZoneInfo InTimeZoneInfo, int InYear)

{

TimeZoneInfo.AdjustmentRule ruleFound = null;

TimeZoneInfo.AdjustmentRule[] adjustments = InTimeZoneInfo.GetAdjustmentRules();

if (adjustments.Length == 0)

{

throw new Exception(InTimeZoneInfo.StandardName + " has no adjustment rules");

}

//Find the correct adjustment rule

foreach (TimeZoneInfo.AdjustmentRule adjustment in adjustments)

{

if (adjustment.DateStart.Year <= InYear && adjustment.DateEnd.Year >= InYear)

ruleFound = adjustment;

}

if (ruleFound == null)

{

throw new Exception("No TimeZoneInfo.AdjustmentRule found for TimeZoneInfo "

+ InTimeZoneInfo.StandardName +" for year " + InYear);

}

DaylightTime outDaylightTime = new DaylightTime(

GetDateTime(InYear, ruleFound.DaylightTransitionStart)

, GetDateTime(InYear, ruleFound.DaylightTransitionEnd)

, ruleFound.DaylightDelta);

return outDaylightTime;

}

Here is the usage.

TimeZoneInfo PacificTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");

DaylightTime daylight = CustomTimeZone.GetDaylightChanges(PacificTimeZone, 2010);

Console.WriteLine("daylight.Start = " + daylight.Start);

Console.WriteLine("daylight.End = " + daylight.End);

Console.WriteLine("daylight.Delta = " + daylight.Delta);