a few yrs ago I had 30 hours at the end of a Thursday night and was only scheduled to do a part time pickup rt on Friday. I was asked to come in Friday morning to do a del Rt route so I'd get my hours. I couldn't I had a doctors appointment and that's why I was working the half day. The manager said that wasn't a problem but I would forfeit my guaranteed pay that week. I think part time works the same way.