Wage reporting when hours change weekly after 10 years as an accounts payable clerk

My hours change every week at my new part-time job and I am afraid of reporting wrongly. There are 10 people counting on me, so I am trying to be careful. Pay posts on a different day from when I work. Did anyone get an overpayment notice from a mistake?

The claimant handbook has worked examples for part-time pay. Mine was clearer than the phone line.