Changing EXIF Date and Time In Raw Files
My Fujifilm X100F camera only comes out of hibernation when I go on holiday. Most of the time, I fail to ensure my camera settings are correct before I take the very first snap. This happened on my last holiday to Loch Lomond.
When it came to the job of carrying out some image processing from RAW to JPEG, I noticed all of my photos EXIF dates were incorrect. I am such stickler for correct EXIF information, including geolocation wherever possible. EXIF information is so useful for cataloging when consumed by photo applications, whether it’s on my Synology or uploaded to Google Photos.
Due to the high number of photos with incorrect date stamps, I needed a tool that will automate the correction process. After a bit of Googling, I found an application called exiftool by Phil Harvey that allows the EXIF date/time stamp to be modified using a method in the documentation called “Shift”.
The exiftool has no GUI (graphical user interface) and will need to be run in Terminal on a Mac or command line for Windows users. The command to use is relatively simple and the only complex thing you will have to do is calculate how many days, months, years, hours, minutes and seconds you need to add or subtract.
In my case, the calculation was a matter of subtracting 3 days from all the photos and the command to do this looks like the following:
exiftool -AllDates-='0:0:3 0:0:0' -m /Volumes/LochLomond
Lets breakdown the command to get a better understanding what each part does.
- exiftool: Runs the application and you have to ensure that your Terminal/Command Line is run in the same directory exiftool is housed.
- AllDates: Modifies all dates in a photo.
- -=‘0:0:3 0:0:0’: Subtract 3 days off the photos exif date. If you wanted to add 3 days, use “+=” instead. The date time format is presented as “<year>:<month>:<day> <hours>:<minute>:<second>”.
- -m: Ignore minor errors and warnings (as stated in the documentation).
- /Volumes/LochLomond: Location to where all the photos reside.
When making mass changes to files, it’s always recommended to ensure you have a back up of all photos for you too fallback on if you accidentally mess up the EXIF update.