We face the same issue. HQ/data center on the East coast w/ locations across the country. Application programs adjust time based on location of user running the program. So user's in Central time zone are -1 off of EST/EDT, Mountain time zone -2 and Pacific time zone -3. Fortunately, we don't have users in AZ or IL/IN (I can never remember which one) which have local variations of the standard time zones.
If your apps run in different locations or your users connect to multiple locations you will have a bigger issue trying to determine the time offset.
Code what you mean,
and mean what you code!
But by all means post your code!
Razalas