Need exiftool
Imagine you live in Tokyo and go to Hong Kong, but forget to change the time in the camera (HK is -1h relative to Tokyo). All your photos would say they were taken one hour before they actually were.
To add one hour to the time fields (DateTimeOriginal
, CreateDate
and ModifyDate
) of all the photos in a folder, just run:
./exiftool -v -AllDates+=1 FOLDER
- GPS coordinates (.GPX files) are usually stored in UTC.
- EXIF data don't have usually a timezone.
This means that when adding GPS coordinates to a photo via Lightroom, the local time of the computer will be used.
To do it properly, the easiest way is to:
- set the computer to the local time of the place where the photos were taken
- add the GPS data
- fix the computer time back
Other option is to temporary change the photo date times with the method explained in the top, but this takes much more time.