When to Work is the website that we use for all scheduling and communication purposes. It is important that you check this regularly to know what is going on.
When needing time off for planned trips or appointments, make a conscious effort to find a replacement. Email out to your coworkers asking for coverage and Cc your supervisors. Then post your shift on the trade board. If no one covers, let your supervisors know.
If you're sick, let your supervisors know as soon as possible. We'll work it out.
Below you can find some help guides taken from straight from When to Work.