Get Time Zone abbreviation given GMT offset with Objective C

Question

Is there a way to lookup a timezone abbreviation when only the temporal offset is known?

Example: Say i'm given the offset of GMT -5, i'd like to display the abbreviation of EST (assuming US) as apposed to GMT -5.

If you initialize a NSTimeZone object with [NSTimeZone timeZoneWithName:@"America/Argentina/Buenos_Aires"], you can get the correct abbreviation by [myTzVar abbreviation];

However, if you initialize it using secondsFromGMT, the abbreviation is always something like "GMT -XXX".