Shifts-
All shifts are published on the Thursday prior to the week that the shifts will take place. So if today is Wednesday, next week's shifts would go out tomorrow.
Shifts are distributed primarily by availability. The more hours you are available, the more shifts you will get.
Shift Drops and Trades-
If you are assigned a shift and need to get it covered, you must release the shift, get it picked up, and have it approved by a manager. Simply releasing a shift doesn’t release you from the responsibility of that shift. Only until it is picked up and approved are you free from the switch.
Similarly, with shift trades, the trade must be approved by humanity before the trade is official.
If an agreement is reached offline for a shift drop or a trade, the manager must be notified before the shift takes place. If the manager is not notified, you potentially may not be compensated for covering the shift.