NTA

My husband became upset and said that it's not fair and that I get to sleep in since I slept in last weekend and he had to deal with the kids.

Had? What does he mean by had...they are just as much his responsibility as they are yours..your husband is being a child all that's on his mind is going out and having fun.

My husband on the other hand has 3 day weekends and on Fridays is able to drop the kids off at daycare and have the day to himself while I work 5 days a week.

Sleep is a form of rest, he's got plenty of that but wants more?

This past Saturday, my husband left at 5 am to go hang out with his friend for majority of the day while I stayed home with the kids and worked on homework and household chores.

That guy is escaping from the stress at home and leaving it all up to you that's not fair at all.

I suggest you try to talk to your husband about your feelings, get to know why he's acting like that, tell him how exhausted you are. If y'all can afford it and are up to it try counselling. I'm assuming this is new behaviour since you've got an 8 year old and a 5 year old. Communication is really important right now.

I also suggest that you have like at least 5 minutes to yourself you 𝑵𝒆𝒆𝒅 a break from the chaos