I'm a SAHM to 2 school aged children.
I do 99% during the week, then at weekends we split it 50/50. It works for us and seems a fair way of splitting it
I do all the big housework stuff during the week (changing beds, cleaning bathrooms, etc, etc) and then at weekends we do the bare minimum to keep the house ticking over (washing up/cook dinner/bung a wash load in). I cook Mon - Fri (we cook from scratch as DD1 is coeliac) then we do one each at the weekend.
My kids are 9 and 13 so we don't have putting littlies to bed/running baths/etc as they just jump in the shower and get ready for bed. He or I go up and tuck them in.
Housework doesn't take up vast amounts of my time - the dog needs a good 2 hour walk a day, we're foster carers so lots of meetings and running around, I volunteer a couple of afternoons a week at DD2's school so I'm busy but not stressed-busy if you see what I mean.
I'm perfectly happy to pick up the lions share of house stuff, but I'm not prepared to be DH's skivvy. Leaving used tea bags in the sink/socks on the living room floor/crusty sports clothes in the bottom of a bag isn't on. He has to pick up after himself and clear away his own mess and it won't kill him to do a bit of washing up after dinner