Improve strategy comments

config/backup.php

@@ -286,27 +286,33 @@
         'default_strategy' => [
 
             /*
-             * The number of days for which backups must be kept.
+             * The number of days to keep backups, ensuring recent copies are available.
              */
             'keep_all_backups_for_days' => 7,
 
             /*
-             * The number of days for which daily backups must be kept.
+             * After the "keep_all_backups_for_days" period is over, the most recent backup
+             * of that day will be kept. Older backups within the same day will be removed.
+             * If you create backups only once a day, no backups will be removed yet.
              */
             'keep_daily_backups_for_days' => 16,
 
             /*
-             * The number of weeks for which one weekly backup must be kept.
+             * After the "keep_daily_backups_for_days" period is over, the most recent backup
+             * of that week will be kept. Older backups within the same week will be removed.
+             * If you create backups only once a week, no backups will be removed yet.
              */
             'keep_weekly_backups_for_weeks' => 8,
 
             /*
-             * The number of months for which one monthly backup must be kept.
+             * After the "keep_weekly_backups_for_weeks" period is over, the most recent backup
+             * of that month will be kept. Older backups within the same month will be removed.
              */
             'keep_monthly_backups_for_months' => 4,
 
             /*
-             * The number of years for which one yearly backup must be kept.
+             * After the "keep_monthly_backups_for_months" period is over, the most recent backup
+             * of that year will be kept. Older backups within the same year will be removed.
              */
             'keep_yearly_backups_for_years' => 2,