Is it possible to be a part-time sitter with a varied schedule?

I love, love, LOVE animals and since I need more income right now I figured I'd give this a shot! Only problem is, I'm working two part-time jobs. I still have plenty of hours available during the week, but the issue is that the schedule can change from week to week. I read somewhere that Rover was like the Uber of pet sitting, but when I started making my profile, it seemed like my availability was pretty locked. My question is, more specifically, is it possible to be a sitter with Rover with a schedule that varies?