Hi there!
I'm new to Exiftool.
I shot a bunch of photographs with a wrong camera time.
I need to shift all of my pictures with +9 hours.
I was trying this line
exiftool -AllDates+=9
Exiftool then successfully changed the date,
but on the mac - the modification date is exactly always the date when i did the command in exiftool (today).
Could somebody help me doing it right?
Thank you a lot,
Christian
I would suggest making sure that the tags in -alldates are correct after running your first command, then you could run
exiftool '-FileModifyDate<DateTimeOriginal' FileOrDir
I don't use a mac but I'm guessing that the modification timestamp you're looking at is a file system timestamp. AllDates is a shortcut for the three most commonly used EXIF timestamps and doesn't include a lot of other possible timestamps. Another thing to watch for might be a variance due to the time zone. At least on Windows, if you set the FileModifyDate, it will be adjusted by the computer time zone. I don't know if that happens on a Mac.
Also, watch out for is the fact that the FileModifyDate is not the most reliable property of a file. Any time the file is changed, this value will be updated, though some programs will let you override this behavior. See the -P option to do this with exiftool.
Quote from: StarGeek on July 09, 2017, 04:47:51 PM
I would suggest making sure that the tags in -alldates are correct after running your first command, then you could run
exiftool '-FileModifyDate<DateTimeOriginal' FileOrDir
I don't use a mac but I'm guessing that the modification timestamp you're looking at is a file system timestamp. AllDates is a shortcut for the three most commonly used EXIF timestamps and doesn't include a lot of other possible timestamps. Another thing to watch for might be a variance due to the time zone. At least on Windows, if you set the FileModifyDate, it will be adjusted by the computer time zone. I don't know if that happens on a Mac.
Also, watch out for is the fact that the FileModifyDate is not the most reliable property of a file. Any time the file is changed, this value will be updated, though some programs will let you override this behavior. See the -P option to do this with exiftool.
FileModifyDate, just as on Windows, is indeed a file system tag. But, unlike Windows, it is recorded properly so doesn't change when you move to a different timezone and/or different daylight savings setting. (This has always strict me as extremely odd: when dst changes, all your file dates change :o That is plainly ridiculous)