I'm not sure if every work place has schedule changes as much as mine does but they happen fairly often. Our protocol, or at least what's supposed to be the protocol for these is as follows: Check your schedule everyday before you leave, it's your responsibility. If there's a change made while your off work for the day you come back to work the manager is supposed to call you and inform you of this. Here's what happens when protocol fails.
Long story short: I was off work from Monday-Thursday. Thursday they call me to tell me my Saturday hours have changed. They didn't however call me to tell me my Friday hours changed from coming in at 4:30am to 8:30am. Then they call me at 6:30 that morning to tell me not to come in at all that day. This is the reason we have protocol.
Me: Off work from Monday-Thursday.
Thursday night I receive a phone call about my Saturday hours being changed. She didn't have to call me since I work Friday, it's a convince some managers will offer if given the time.
Friday: as of Sunday I'm scheduled 4:30am-1pm. I've never worked a 4:30 shift before since I'm primarily a front worker and that shift is reserved for the kitchen. So I get to work at 3:40 to observe the times everyone gets there and such. Well 4:20 rolls around and everyone gets there and we all go into the building. I'm looking around for the person scheduled to train me and when I don't see them I go look at the schedule. I'm not scheduled to come in until 8:30am. Four. Hours. Later. So I go home and start on the homework I put off the night before to go to bed early. 6:30 rolls around I receive a phone call. I don't go in to work at all that day.