Enter the previous month's slate. Checked days indicate "weekend" duty which is weighted higher. "Demo" loads a slate of generic names for testing.
Adjust all available personnel for upcoming month's duty. "Fill" autofills names from the previous month. Enter exemptions as days separated by commas (e.g. 1,13,15).
Calculate optimal slate for upcoming month. Adjust the minimum span between shifts as desired (if the calculation returns no result after 1-2 seconds, try modifying this parameter).