Wage reporting when hours change weekly (Hartford)

I picked up part-time shifts as a nurse's aide and I am confused about how to report them. It has been weighing on me all week. The form asks for gross earnings, which I do not see until later. Do you report when you earned it or when you were paid?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.