Google handles GMT and UTC but doesn't handle offsets from there and, frankly, it's understandable and I wouldn't bother either. What it does handle though is countries and their DST settings:
A regular complaint I have with google is (simplified example) converting EDT to MST. Google will “helpfully” correct me and convert EDT to MDT instead, which is explicitly not what I asked for. It’s stupid (I can usually figure it out on my own) but that would be a huge win for me.
