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.
Of course, you might want to back up more than your genealogy files. Family photographs, your checkbook register, all sorts of word processing documents, email messages, and much more need to be backed up regularly. Why not do that on the first of each month?