I probably should have given more details. (sorry english is not my first language)

I received my check for Period (March 16 - March 29).

March 30 was our last operation day. I got paid for Mar 30th. (my montly salary is 3000, before taxes and I worked 6 days a week. So they gave me $115 for my work on Mar 30th). But I still worked on March 31 and April 1 (handing out checks and paperworks). I worked half a day for both days. and they paid me $115 for both days. and I assumed they did this because the money that I thought was my bonus. Now that I know it's not. Is it legal for them to pay me daily and half a day salary for the last 2 days I worked?