I have five days and around 17 hours a week. I try to put my classes between 11-4pm, but unfortunately since I'm in higher years now - lectures for obscure subjects start at 9 so I end up having 9-3 most days, usually with big breaks.
Maths lectures are usually not online. Only my Arts ones are online.
And no lab work for me, I don't do "Science" as in Chemistry or Physics or Biology or Geology. My science major is maths - so I do maths subjects, and my arts major is English - so I do English subjects (with a minor in Economics).