find . -type f -mtime 2 (exactly 2 days)
find . -type f -mtime +2 (2 days or more)
find . -type f -mtime 3 (exactly 3 days)
find . -type f -mtime +3 (3 days or more)
find . -type f -mtime 4 (exactly 4 days)
find . -type f -mtime +4 (4 days or more)
etc.