Backup only the Current month directory only

Hi All. 

I have mount point like /backup then inside there are directories: 1 2 3 4 5 6 7 8 9 10 11 12 (each directory represent the month). Since the who whole /backup directory is quite huge, I want to backup only the current month, so for example this march I want to backup /backup/3 directory only (or plus a month before /backup/2 for redudancy) . 

Is that any easy way to do that? 

Thank you.

Iwan Tamimi