Try Shush! I love it. I assume that you can recall to silence your phone as you walk onto campus or into class for the first time every day. Shush will allow you to silence your phone by pressing the sound key all the way to silent mode then you get a pop-up to choose to either silence it for xx hours or until a certain time of day.
(You may want to make sure all your notifications are truly silent. I have only used this occasionally and may not have all the notifications you have.)
https://play.google.com/store/apps/details?id=com.publicobject.shush&feature=nav_resu lt#?t=W251bGwsMSwxLDMsImNvbS5wdWJsaWNvYmplY3Quc2h1 c2giXQ