Short answer
Each AmberTime task keeps a backup record for its source. On the next run, AmberTime scans the Photo Library or Files folder, compares it with the record, and transfers only items that have not already been backed up.
When this is useful
Incremental backup is useful for large iPhone libraries because the first backup may be big, but later backups should not start over. It also helps creators keep separate sources organized: one task for the Photo Library, one for DJI footage, one for downloads, and another for project folders.
For old-photo archiving, date-range tasks can also stay incremental. For example, a task for photos before 2024 can be run again later without recopying items already recorded as backed up.
What AmberTime does
- Scans identifiers first before fetching full details for new Photo Library items.
- Records successful backups per source and asset key.
- Skips files that are already known to be backed up for that task.
- Uses temporary .part files for in-progress writes.
- Allows multiple independent tasks for different sources.
Things to know
Incremental backup depends on the task record. If you create a new task for the same source and destination, it may need to build its own record. If a drive disconnects during a run, completed files are recorded and the next run can continue from remaining items.
AmberTime does not delete source photos or folders after backup. Cleanup remains a manual user choice after the archive is verified.