How Does Appen Work?

Hey y’all. So I got a job as a Social Media Evaluator with Appen about a week ago (US based). I’ve been doing the work fine, but I’m mad confused about the whole “Appen workweek” and how the extra hours work. I’m working with Uolo btw. Does the workweek start on a Saturday or on Monday? And if I want to put in more than 20 hours a week: one, do I have to email them and let them know? and two, do I work my extra hours on Saturday + Sunday or on Thursday + Friday? I’ve been sending Appen a lot of emails recently so I didn’t wanna bombard them too much lmao