Now that you have successfully performed and tested both a duplicate and an archive, it's time for the last important step: scheduling these backups to occur automatically.
As I mentioned earlier (see Scanning Methods), some backup software runs all the time in the background, in some cases automatically adding newly created or modified files to your backup as they're saved or shortly thereafter. If you're using such software, you don't have to worry about scheduling—your backups are already automated. Likewise, if your backup software is designed in such a way that setting up an initial backup also creates a schedule, you're all set.
If not, take a few extra moments to tell your backup program when you want it to run. Backup software usually makes it easy to put a given backup procedure on a simple, recurring schedule—e.g., Daily Archive every night at 11:00 PM, Weekly Duplicate every Sunday morning at 6:00 AM. But if you have multiple sets of media, creating an alternating backup schedule can be more complex. In this case, you might want Bart Daily Archive to be stored on Bart Archive Disk every night this week, while Lisa Daily Archive is stored on Lisa Archive Disk every night next week, and so on. Instructions for setting up such schedules in Retrospect are at the Online Appendixes.
When choosing times and days for your backups to run, keep in mind these considerations:
Will the destination media be ready? If not, will you be available to insert or enable it?
Do you need to supply a password—for the backup software itself, or to mount a network volume? If you cannot store such passwords in your Keychain, or do not wish to do so, be sure the backups run when you're present to enter the passwords.
Will the backup slow down your computer? If so, think about scheduling it for a time when you're not busy.
Regardless of your software, begin by scheduling archiving, which will probably run one or more times every day. Then schedule duplicates, choosing a time of day well before (or after) your scheduled archive run(s) to avoid conflicts between the two schedules. Repeat as needed for each media set you will be using.
Be sure to make a note of your duplication schedule in your favorite calendar application or on a paper calendar so that you will know when to swap media for off-site storage (see Off-site Storage, a few pages ahead). For example, if you do a weekly duplicate on Sunday, you might create a recurring reminder to swap media every Monday morning before work.
After setting your backups on a schedule, check them periodically to make sure they are running as you expect. Some backup software provides logs for this purpose—or you can look at the files on the backup media and confirm that they are as recent as they should be.