TimeToSignUp added the ability for admins to request multiple sign ups for one item.
Entering the quantity allows a participant to sign up for multiple items and/or allows multiple participants to sign up for the same item. In the example above (Clean-up Crew: 4:00 - 4:45), the admin is allowing 5 participants to sign up for the clean up crew.
When a participant views the TimeToSignUp sheet, they will see the option to choose a quantity: