What does a game designers schedule look like

Depends on the studio and the scope of work. If you're EA with a massive scope of work and a 3 year development schedule, expect to work 7am-6pm weekdays and possibly weekends and that's just as QA or associate designer. In a smaller setting, you can expect to work something like 12-6pm on Mondays, Wednesdays, and Fridays. In rare cases, you can work 7am-7pm Mondays and Wednesdays (back in my days with Xfinite). At home, however, I would dedicate at least an evening everyday so that way you still have time for the rest of your stuff.

Overall, the schedule is varied depending on what you're doing, where, and how long you have until shipping. Starting off, it will be stressful part-time because you need to juggle with work and school, but once you do full-time design work, it's pretty easy and relaxing since it will be a regular schedule. But just know that if the scope gets too big and the shipping deadline is closing in, you are likely expected to work overtime. I worked an entire weekend without sleep to fix a several graphical bugs and code to prepare for shipping. But there was one contract where I was done in a month. (I was the programmer).

So, in short, it depends on the time required. It's a long roundabout answer, but it truly is situational based on what you're creating.