formula help for staffing issue

I'm not entirely sure what your table represents, unless it is people needing to be starting or on shift at a given time.

If so, I'm a little bemused given that you have only 55 staff and every day, except at the weekend, you have a requirement for bums on seats exceeding that from 08:30.

I'm guessing that means you don't have enough people to cover even the minimum requirements.

Am I missing something or have I wildly misinterpreted the data (and your question)?

Regards