Is orientation really necessary?

I didn't realize that orientation was a 3 day event (which is also mandatory according to the website) with the first day running from 8 am to 9 pm. I've already made plans for the 2nd day that I can't skip out on. Not to mention I live about 2-3 hours away from Davis so if I want to arrive on time to Day 1 of orientation I'll have to start driving at 5 am which I do not look forward to. Is it fine if you skip out on some days or all of orientation? There's no punishment for skipping out right?