Determine Whether Daylight Savings Time (DST) is Active in Java for a Specified Date

Question

I have a Java class that takes in the latitude/longitude of a location and returns the GMT offset when daylight savings time is on and off. I am looking for an easy way to

Answer 1

You're going to have to do a bit more work using those coordinates and figure out which time zone they're in. Once you know which TimeZone that is, the isDayLight() method would be useful.

For example, you have no way of telling whether -0500 is EST (US/Canada Eastern Standard Time), CDT (US/Canada Central Daylight Time), COT (Colombia Time), AST (Brazil Acre Standard Time), ECT (Ecuador Time), etc...

Some of these may or may not support daylight saving time.