Quick answer: turning off "Automatically adjust clock for Daylight Savint Time" in Vista fixes all the time problems that I've been seeing for the last few days! OK, I've been experimenting for a while, I think exiftool is working fine on 5.10. I was initially running Perl 5.8 but had problems so switched to 5.10 and I think I've tracked down the culprit to be Windows Vista! Sorry Phil! Because I ended up chasing my tail for a bit, I decided to take four test photos with known times on my camera and see what ended up. My camera also has a Daylight Saving time setting, which I believe is superfluous to this, but just wanted to make sure I controlled all the variables. So I set the cameras clock to 2030 each time and once in summer and once in winter; repeated for Daylight saving time for completeness. Notice how Vista shifts the time by an hour in winter time! The other peculiar effect I've discovered, is that Vista also shifts the File Modification Date/Time by an hour if the file is copied from the camera during winter time (or when Vistas local clock is set to winter time). Is the solution to leave "Automatically adjust clock for Daylight Savint Time" turned off and manually change Vista's clock twice a year? Such a pain!! IMG_1166.JPG: ============ Set on camera: 15.08.2008 2030 Daylight saving time ON exiftool.pl: File Modification Date/Time : 2008:08:15 20:30:12 Date/Time Original : 2008:08:15 20:30:13 Create Date : 2008:08:15 20:30:13 Modify Date : 2008:08:15 20:30:13 Photoshop: exif:DateTimeOriginal: 2008-08-15T20:30:13+01:00 Vista Date Taken: 15/08/2008 20:30 IMG_1167.JPG: ============ Set on camera: 15.11.2008 2030 Daylight saving time ON exiftool.pl: File Modification Date/Time : 2008:11:15 20:30:04 Date/Time Original : 2008:11:15 20:30:05 Create Date : 2008:11:15 20:30:05 Modify Date : 2008:11:15 20:30:05 Photoshop: exif:DateTimeOriginal: 2008-11-15T20:30:05Z Vista Date Taken: 15/11/2008 21:30 IMG_1168.JPG: ============ Set on camera: 15.08.2008 2030 Daylight saving time OFF exiftool.pl: File Modification Date/Time : 2008:08:15 20:30:04 Date/Time Original : 2008:08:15 20:30:05 Create Date : 2008:08:15 20:30:05 Modify Date : 2008:08:15 20:30:05 Photoshop: exif:DateTimeOriginal: 2008-08-15T20:30:05+01:00 Vista Date Taken: 15/08/2008 20:30 IMG_1169.JPG: ============ Set on camera: 15.11.2008 2030 Daylight saving time OFF exiftool.pl: File Modification Date/Time : 2008:11:15 20:30:04 Date/Time Original : 2008:11:15 20:30:04 Create Date : 2008:11:15 20:30:04 Modify Date : 2008:11:15 20:30:04 Photoshop: exif:DateTimeOriginal: 2008-11-15T20:30:04Z Vista Date Taken: 15/11/2008 21:30