I have a calender for my school schedule. I usually like my phone to ring, but during class I can't have that happen. I miss a lot of calls because I always have my phone in vib or silent because of school. Is there a way that I can the phone in vibrate when im in class or other meeting type events? I'm using the calender that came with my phone synced to my google calender. I'm not sure if the calendar software being used on my phone is an android default, htc, or google calender software. The phone is evo4g on 2.1.