Deductions & credits

I have a similar question but want to be more specific. My school is considered my tax home so I do understand that mileage traveling to the school is not deducible as those miles are considered commuting miles. However, my salary is based on 187 contracted days. If I am required by my job to go to my school on a Saturday which is not part of my 187 contracted days but I am not compensated financially for it, could I deduct the mileage to go to the school on those particular days?