On the designated day, the Weekly timer is reset and a backup reminder is displayed when you quit JWM. The backup reminder exists to remind you to backup your dictionary files to protect your study progress. This is a form of insurance in case your files are somehow damaged or accidentally deleted from your computer. You are strongly advised to get into the habit of backing up your exercise dictionaries on a weekly basis (at least). Just imagine that you had been exercising for the last year and your exercise dictionaries were corrupted in some way - an entire years worth of accumulated tailoring information would be lost!
You should also backup using a technique called a Rolling backup. In this technique, you create a folder with the date of the backup in the name (such as 'JWM backup 4-4-97') and then copy your exercise dictionaries into it. This means you will accumulate backup folders over time. When you have around a months worth of backups, start deleting the earliest one when you add a new one.
It's best if you do your backups on a different disk to your hard disk, such as a Zip cartridge or floppy disk (you may need to compress the folder to fit it on), but backing up to your hard disk is a reasonable strategy. The only downside of this is that if your hard disk dies, so do your backups. Losing data is one of the most heartbreaking problems that
may occur when owning a computer, but with some planning you can secure your information. Don't let it happen to you!