When enabled, dashboard Snapshots capture the state of a dashboard at a certain time and frequency that you set. This allows you to go back and review what dashboards and data looked like in past weeks.
To enable Snapshots, open your dashboard and from the sidebar, click Settings. Scroll to the bottom and select Snapshots Enabled. You can adjust the time (in UTC) that the Snapshot will be taken each day. Click Update.
To review your Snapshots, click View Snapshots in the sidebar. They will be organized by month, and within each month you can pick days to look at.
You may want to be aware of how many of your dashboards are using Snapshots and space the Snapshot hour out so as to not overload your database.
The Snapshots are stored statically as SVG and never change. If you rearrange your dashboard or move around some charts, the past Snapshots will not change, meaning that Snapshots are a helpful way to get an unaltered look into what your data looked like in the past.