Recordings of new (first-run) broadcasts are guaranteed to be saved for a week. Re-runs are guaranteed to be saved for three days. After that, it depends on how much and how often you record. Due to storage space constraints, the more you record, the sooner your oldest and least important recordings will be automatically deleted.
A recording that is expiring and will be deleted soon is indicated by a warning icon:


Take caution! Once a recording is slated for expiration, it can't be undone.