>>I am wondering how many states in US have different time zones in the state itself and if there are different time zones per area code?
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>>If this is the case, how can we figure out the GMT date /time based on the area code and the time which most likely was recorded in local time?
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>In additional to what Hank said, also keep in mind that there are parts of the United States that don't participate in daylight savings time.

Even a bit more tricky than that... for example Arizona doesn't use daylight savings time -- EXCEPT if you are in a national park where they do use it.

>I forget if it's still this way.....but years ago I had co-workers in an office in Indianapolis. They are considered central time, but at least years ago they did not change the clocks in spring and fall. So part of the year we were on the same time and part of the year we weren't.
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>At my current place, we deal with Eastern, Central, and Mountain times. Corporate is considered Eastern and all data is stamped with respect to Eastern. So a user in the Mountain area knows that when a row says "7 AM", it's always referring to Eastern time.
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>Certainly not the only way it can be dealt with....