Snapshot policy event logs are maintained containing timestamps associated with changes to the snapshot policy over time. Storage group event logs are maintained for each storage group associated with the snapshot policy containing timestamps associated with changes to the storage group over time. Snapshot compliance is calculated by creating a timeline of the snapshot policy and creating timelines for each of the storage groups associated with the snapshot policy. The snapshot policy timeline and storage group timelines are intersected to calculate how many snapshots should have been created for each storage group associated with the snapshot policy during each snapshot policy timeline interval. The sum of all snapshots that should have been created and still be maintained at a particular point in time is compared with an actual number of snapshots maintained for the storage groups by the storage system at that point in time.