How do you report hours that vary week to week?

My hours change every week at my new part-time job and I am afraid of reporting wrongly. Thank you in advance. Sometimes my paycheck is late by a week. Do you report when you earned it or when you were paid?

Report honestly and keep your stubs. An honest small error is much easier to fix than a missing report.

I estimated and then checked my pay stub. When there was a small difference I wrote to the agency to correct it.