Fix camera clock / timezone offset.
Shift Date Taken across a folder by ±h:m:s, or derive the offset from one photo with a known-correct time. Files never leave your device.
The step that breaks geotagging
Camera clocks drift and travel across timezones. GPS tracks are in UTC. If you geotag without fixing the offset, every pin lands hours away. This tool is that fix — standalone, or as prep before geotagging from a GPX track.
Photograph the GPS clock, then type what you see
Shoot your GPS (or phone) screen showing the time. Pick that JPEG as the reference, enter the time displayed, and we compute the delta against the camera's DateTimeOriginal. The same offset applies to the whole batch. We do not guess from pixels — you confirm the digits.
Offset is a fixed delta, not a timezone database
EXIF DateTimeOriginal has no timezone. We treat the digits as wall-clock and add your seconds. If your trip crossed a DST boundary mid-batch, split the folder and use two offsets — we will not silently invent zone rules.
Nothing is uploaded
EXIF reads and writes run in your browser (in a Web Worker). You download copies; originals are never modified in place.
Common questions
- How do I change photo Date Taken in bulk?
- Drop a folder, enter ±hours:minutes:seconds, preview the new DateTimeOriginal values, then download copies. Originals stay untouched.
- How does derive mode work?
- Photograph your GPS or phone screen showing the time. Pick that JPEG as the reference, type the time you see, and we compute the delta against the camera’s DateTimeOriginal. The same offset applies to the batch — we do not OCR the pixels.
- What about DST or mid-trip timezone changes?
- Offset is a fixed delta, not a timezone database. If your trip crossed a DST boundary mid-batch, split the folder and use two offsets. We will not invent zone rules.
- Is this for geotagging from a GPX track?
- Yes — wrong camera time is the step that breaks geotagging. Fix the offset here, then use the geotag tool so pins line up with the track.