Is there a way to find out the current daylight savings state

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Is there a way to find out the current daylight savings state

buddy__a

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November 9, 2011 at 8:37 am

#150617

Without any pre-populated tables, or external parameters passed is it possible to find out if the server is in daylight savings time?

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Lowell SSC Guru Points: 323518 More actions · Answer 1

if you know what offset your timezone is, you could calculate it;

for example in Miami Florida, i'm -5 from GMT , but when it's daylight savings, i'm -4;

by getting the diff between GetUTCDate and GetDate, you can see what it is currently...but you have to know what "normal" offset is.

select getdate(),getutcdate(),datediff(hh,getdate(),getutcdate())

--(No column name)(No column name)(No column name)

2011-11-09 11:24:54.9902011-11-09 16:24:54.9835

Lowell

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buddy__a Hall of Fame Points: 3222 More actions · Answer 2

The problem is that the DB server may be in one location while the clients could be spread throughout multiple time zones. So, I store the datetime data in UTC. It works fine until the the daylight saving time changes. Then all the scheduled notifications are off by one hour. If I knew it was DST or not then I could know whether to offset the time by an hour. Also the notifications are processed without any input from the client so I don't know what time zone they may be in. So, when a notification is scheduled the item is queued for delivery when the UTC time arrives not through some user client request.

Lowell SSC Guru Points: 323518 More actions · Answer 3

if you have a datetime column for WHEN the data was actually entered, you could compare that to a TallyCalendar table(which you wanted to avoid) and get the DST offset.(ie if the data was entered on 7/23/2011, my TallyCalendar shows DST in hte US ranges:

select * from TallyCalendar where YearNumber=2011 and IsDaylightSavings=1

US DST Begins 2011-03-13 00:00:00.000

US DST Ends 2011-11-05 00:00:00.000

your application(web page?) could give you the users local time after at least one page submission,but that's all i can think of.

Lowell

--help us help you! If you post a question, make sure you include a CREATE TABLE... statement and INSERT INTO... statement into that table to give the volunteers here representative data. with your description of the problem, we can provide a tested, verifiable solution to your question! asking the question the right way gets you a tested answer the fastest way possible!