How many days per year are scheduled?

I'm planning on getting the complete level 5-7 in June after we are done with level 4-5. How many days are scheduled? Is it a full 36 weeks with 5 days a week of lessons(180 days total)? If it is, would it be easy to condense it to a 4 day week by doubling up on some days without it becoming overwhelming? We use a 4 day week for 36 weeks, for a 144 day school year...

I had no issue condensing it with my older daughter and plan to do it again this year. It did mean I had to look ahead and think about what to move around but it was always doable.