git find last file modification on all branches?
Solution 1:
git log --all --since="2 months ago" --until="2 weeks ago" -- path/to/file
If you also need branch names for a specific commit, use git branch --contains commit-id.
Solution 2:
I don't know of a quick way to do this for a single file across every branch (only git diff between two branches), but I would definitely use git blame and/or git diff to figure out the rest if you wind up having to do this branch by branch.