Generally they do not like CPs to work more than 16 work hours a day (as this will push you into double time) or 7 days a week. Keep in mind, with a 16 work day you get 2 lunches, so you'd actually be at work for 17 hours.
International CPs are typically capped at 37.5 hours, because of their work visas/classes. This is lifted during peak seasons.
And in case someone is interested - the minimum hours a CP can be scheduled is 30 hours a week. Of course this does not include time requested off, if you want to give away a shift or if you ER (early release) during your shift..