A simulator to experiment with different backup schedules and prune options.

Schedule

Select weekdays with the combobox and input hour and minute specification separated by a colon, i.e. HOUR:MINUTE. Each of HOUR and MINUTE can be either a single value or one of the following:

Pruning

Prune lets you systematically delete older backups, retaining backups for the last given number of time intervals. The following retention options are available:

keep-last <N>
Keep the last <N> backup snapshots.
keep-hourly <N>
Keep backups for the last <N> hours. If there is more than one backup for a single hour, only the latest is kept.
keep-daily <N>
Keep backups for the last <N> days. If there is more than one backup for a single day, only the latest is kept.
keep-weekly <N>
Keep backups for the last <N> weeks. If there is more than one backup for a single week, only the latest is kept.

Note:

Weeks start on Monday and end on Sunday. The software uses the ISO week date system and handles weeks at the end of the year correctly.

keep-monthly <N>
Keep backups for the last <N> months. If there is more than one backup for a single month, only the latest is kept.
keep-yearly <N>
Keep backups for the last <N> years. If there is more than one backup for a single year, only the latest is kept.

The retention options are processed in the order given above. Each option only covers backups within its time period. The next option does not take care of already covered backups. It will only consider older backups.

For example, in a week covered by keep-weekly, one backup is kept while all others are removed; keep-monthly then does not consider backups from that week anymore, even if part of the week is part of an earlier month.