When I get home from work in the evening, all I have time for is to cook supper and do the washing up.
On the weekend, I have to pay any bills and do the household budget, do grocery shopping, laundry, ironing and clean the house.
If I go out on Saturday and Sunday, the house doesn't get cleaned for 2 weeks.
If I stay out too late on Friday or Saturday night, I end up sleeping later than I want to on Saturday and Sunday morning and don't get enough of my chores done.
I don't even have children. If I did it would be at least 10x harder.
How do they do it?
How sad

Does your husband not help at all? Could you not look to be more organised so some of this stuff could be done quicker?
To be honest, I don't really understand how the things you've listed could take you all week and all weekend? Do you have a really big house?
Pay Bills - Could you use something like Excel or mint.com to help? Or consider switching to Direct Debits? I don't think I spend more than an hour a month paying bills. What do you need to do? Call them up and pay over the phone? Could you pay online or call during your lunch hour? Then you could log everything into a google doc to access from everywhere. My Water, Rent and Council tax are all Direct Debits, we get electricity and gas quarterly, but I just log in online to send the meter readings and that's it.
Grocery Shopping - I get my Groceries delivered from Ocado, I pay £10 a month for unlimited deliveries and get one £40 shop delivered a week. It's really simple and takes almost zero time with auto-shop

Laundry - We have three small laundry bins and laundry gets separated as we go, as soon as one is full it gets put in the washing machine and either tumble dried, or if the weather is lovely, hung outside. Again, as long as it doesn't build up it doesn't take much time, sometimes I put a wash/dry on before we go to bed so we have clean clothes in the morning. We probably do no more than two loads a week, easily doable on the weekend.
Cleaning the house - We got the house spotless and then clean as we go, so like if I cook dinner I'll clean as I cook and then my DB will do all the dishes and wipe the surfaces afterwards, sometimes we'll both be in there, he'll be cleaning behind the fridge or something whilst I cook. We Vacuum on weeknights and tidy when things get messy, we now tend to clean on Saturday morning before we go out, we're normally up pretty early then spend a couple of hours on the house before going out at around 11am

I, like phatbeetle probably work 70+ hours a week, but always find time to be out all weekend, and often during the week as well. My Boyfriend and I actually had a discussion a couple months ago as I thought he was leaving way too much to be done on the weekend and not enough time for fun and it was getting me down, now we try and do as much as possible during the week so we can spend more of our weekends going out and having fun
Like this weekend, last night the boy and I went to dinner after work (around 7-9:30) then it was still light so we went to the park to go for a bike ride until it got pitch black (around 11) then we came home and watched TV for an hour, got up at 8:30 this morning. I've put a load of laundry on already (wash & dry heh heh), and I've done the coffee mugs from this morning, I also sprayed the shower done after I got out.
We're going out in about an hour to meet friends at Borough Market, then we're going to Rough Trade to hunt for Records, then we have a Birthday Party this evening until late, tomorrow I have 10 people coming over for a BBQ, then we'll go to the pub. There's plenty of time slots in there to get things done, but really there's not much to do as we've been doing little stuff all week

During the week I don't get home until 7:30 at the earliest, my DB commutes London to Brighton so is home around 7, often I'll ask him to do some dinner prep work like chopping onions or pre-heating the oven or whatever, so when I get home I just breeze through dinner. We have dinner around 9pm, which still leaves 2 hours before we go to bed.
We go to be around 11-11:30, DB gets up around 6:30am I get up at 7:30am. So we're both out at least 12 hours a day during the week.