Cameras (really the EXIF Capture Time tag) has no provision for GMT Offset at all. The computer's GMT Offset is always used from the host computer. This much has always been true in Photo Mechanic (at least as long as I can remember.)
DST is enabled/disabled on the host computer. In countries (or states/provinces) that don't observe DST, the DST offset would always be zero. I know for certain that Mac OS X can automatically determine when to apply DST but I don't know if Windows does offhand. PM 5 is now asking the computer: Is DST in effect now? If it returns NO then the GMT Offset is not modified. It shouldn't matter which day a particular country/county/state/province enables it as long as it is observed consistently on your computer system.
If this turns out to be an actual issue for you all, we'll be sure to make a preference in an update build to make it off by default and folks like Warren can turn it back on.
Hi Kirk, I'm still a bit confused. What does this fix actually change? if I look at the exif data, I do see times with e.g., +09:00 (which is correct as they were taken in Japan) or +01:00 (which is my own time zone). I guess, with daylight savings in effect
at the time the shot was taken the times should actually read +10:00 and +2:00? Is this what your fix does?
As a side note: I found my newer cameras do actually record both the DST flag as well as the timezone (as e.g.,+ 09:00), older camera's only register the timezone, or nothing of this sort at all.
I think, ideally, PM should be able to adjust these fields in the Adjust Capture Times in the tool menu. This way you can correct mistakes properly (forgotten to set DST, or change the timezone).