Find files modified within a certain time range

To find files by age, use find’s -mtime flag. The sign works backwards from what feels natural.

The Fix

find . -mtime -1   # modified less than 1 day ago
find . -mtime +7   # modified more than 7 days ago
find . -mtime 3    # modified exactly 3 days ago (rarely what you want)

For finer granularity, -mmin does the same thing in minutes:

find . -mmin -60   # modified in the last hour

Why the Sign Feels Backwards

-n means “less than n”, +n means “more than n”. Read -1 as “younger than 1 day” and +7 as “older than 7 days”, not as a literal day count.

Gotchas

• -mtime is content modification time. -atime is last access time, and many filesystems don’t update it on every read, so it’s an unreliable “last used” signal.
• A bare -mtime 3 (no sign) means exactly between 3 and 4 days old, which almost nobody wants. Use -1/+n ranges instead.