They can only guarantee you the ONE day a week, but you usually end up working more as you learn more routes.
With Christmas packages coming in, you may be asked to help deliver packages on any/all routes many days. Our RCA's are already do that in our office.
After you are trained and settled into your office, if you don't get enough hours you can ask to be loaned to another office in need of help.
If your office has Sunday Amazon you can/will be working on Sunday delivering packages.
If your office does NOT have Sunday Amazon you can check around for an office within 50 miles that does and be loaned to them on Sunday.
There are many opportunities to gain hours, but first concentrate on training in your office to be proficient on your assigned route.
Your PAID training is about 3 weeks all together. Orientation, driver's training, RC Academy, in office On the Job training with the Regular carrier.
Hopefully your Regular will take off a few days after training to let you run the route by yourself to get better at it.
It is tough at first, but hang in there is gets easier the more you do it.