Multiple Entry Periods
When running a sweeps with multiple entry periods like in the example below, it is best to create a separate, duplicate snapshot per window.
As mentioned previously, reports are created per open snapshot in the Analytics section. By duplicating and creating a snapshot per entry period, you are naturally dividing the reports by entry window and are able to randomly select winners within their chosen entry period.
Alternatively, if you choose to keep all entries on one snapshot when you have multiple windows, you run the risk of choosing a winner for a given period that they did not enter for.
Multiple Entry Periods with Overall Winner
The only time it would be best to have multiple entry period sweeps on one snapshot is if you have a sweeps that has an overall grand prize winner at the end. In this case, it is best to have the campaign run in 1 snapshot. You can use the overall report to manually choose a random winner by day and select your grand prize winner using the random generator.