As you may know,I am a full-time student at ___________ College. A appreciate the opportunity the company has afforded me and I like my job, but unfortunately, as circumstances would have it, I need to rework my schedule to enable me to take a very important test at school on July 27th..

This is conflict is a very rare occurrences and I would not impose on you if this were not so important. (If you have never needed to do this before, mention that here).

I would be glad to work any other day, doing any job you have if you could only help me with this. I assure you it is highly unlikely I would ever need to ask this again.

Thank you for working with me on this problem.

Very Truly Yours,

(This person would obviously understand that your college degree is important to you. You don’t need to tell him. (or her)

sometime like

Because of an education obligation that I must tend to, I can not work my rotation on (what ever date and time). Could it be possible to work my rotation on another day?

I am sorry for the inconvience.