Kidney Stone surgery #3

I am now scheduled for my third surgery for this year.  Each one has dealt with the same kidney stone, that I have had for about a year and a half.  I will have surgery, on Thursday, November 8 at 1 pm. I wanted it done on a Friday, since it one be an easy day for my sub, but is not.  I am supposed to be able to go back to school the next day.  But I will be prepared for a sub for the next day, just in case.