An illustrative data storage system captures snapshots of a data structure based on snapshot creation schedules and sets retention periods for the snapshots based on snapshot retention schedules. The data storage system eradicates snapshots based on expirations of the retention periods. In certain examples, the data storage system determines a rule to use to capture a snapshot based on a state of snapshots within one or more lookback periods and/or based on a set of rules each defining a snapshot capture schedule and a snapshot retention schedule.