Hello! Fellow writer here! 
Honestly, there's really no 'best' days in my opinion. It really doesn't matter which days you choose; just choose a schedule that works best for you! 
I'm also a student and will be starting school soon, agh! But, if you have a backlog of chapters, you can always schedule them out so that it releases at the set time you've chosen! I'm doing this for my novels since there is literally no way that I will be writing and updating like I have been this past year 