It used to be, pre-Lauren, that Drew had even days and William had odd days. Now that Lauren is old enough to be in the mix I had to change it.
Now it goes in order of birth throughout the week. Monday - Drew, Tuesday - William, Wednesday - Lauren then repeat. Thursday - Drew, Friday - William, Saturday - Lauren. Sunday - Mommy's choice. On Sundays I can choose someone who has shown a lot of kindness or willingness to help throughout the week or if I'm pissy and don't want kids in the mix I can do everything myself. It works out really really well. You hear a lot of, "It's MY day! I get to push!" and then it's the end of discussion. It's pretty awesome.
A bonus that I've added is that on your day you get to have a piece of gum. GUM! As far as each of my kids is concerned GUM is the best thing ever invented. They just can't wait for their day.