Tell me what to do here, folks.
I encountered a rat's nest of problems with geotagging recently because I'd left my camera clock to local time on a vacation eight time zones away. Some have suggested to me that I change my camera clock to Greenwich Mean Time (GMT), the closest thing the planet has to an absolute time zone reference point, as an easier way to embed location information in my digital photos.
I've been reluctant to make the GMT switch because I didn't want a photo I took at, say, 8 p.m. California time to be indexed on my computer as 4 a.m. the next day. Maybe I'm too parochial, but I sometimes want to know the real time I took my shot, not some relative time where I have to subtract seven or eight hours. And of course the issue extends to photo-sharing sites: might a friend be unable to find a wedding photo I uploaded, because he's searching by date and doesn't know to look one day in the future?
But on the flip side, I plan to geotag my photos routinely now, and I don't want to repeat my earlier problems.
Feel free to e-mail advice to me directly at email@example.com or post below in the Talkback section so others can benefit.
Also, for finer time adjustments, here's a good tip I heard from Jeffrey Early, author of the GPSPhotoLinker geotagging software (who was one of the folks who suggested I move to GMT). Geotagging software often lets you precisely synchronize your camera and GPS times, but what's the best way to see if your camera clock has drifted away from your GPS. Take a photo of the GPS clock and compare the subject of the photo with its timestamp.