Considering how easy it is too lose your data, we all need to heed this advice.
From “Eastman’s Online Genealogy Newsletter” for November 01, 2013
It is the first day of the month. It’s time to back up your genealogy files. Then test your backups!
Actually, you can make backups at any time. However, it is easier and safer if you have a specific schedule. The first day of the month is easy to remember, so I would suggest you back up your genealogy files at least on the first of every month, if not more often.