Cat wants 2 litter boxes... one for peeing, one for poo

We were gone for 3 days/2 nights and decided to see how P.Kitty could do on his own (hoping to get away for weekends!). I clean his litter box every day like clockwork, so I wasn't sure how he'd he do with unclean litter. My solution was to put out two litter boxes. Well, he only peed in one, and used the other box for poo only. I wondered if it was a fluke, so I've maintained both boxes, it he has kept it up for 3 weeks now.

I'm not concerned, but is this normal behavior? Because I use Feline Pine, this actually saves me money as I only have to change the "pee" only (or the express box, as I call it) weekly - the other box is fine for >2 weeks.

Yes lots of cats prefer to have one box to pee and one to poo in. It is always recommended to have one litter box per cat plus one extra.

It is normal, but a lot of kitties don't have the litterbox facilities available to exhibit this behaviour.

My four cats used to have two boxes, when I set up a third they suddenly started to seperate the poo and pee boxes.

When I got a 2nd kitty, I added a 2nd box. I noticed that they both used both, but not one exclusively to pee in and one to poop in. My cats are just weird!