So 12 hours.. wait.. I don't sleep for 12 hours a day.... hmm.. better make that 16 hours!
I'm happy to do this (you need above a certain karma threshold to create polls - I forget what it is) but if the OP would rather not then that's fine too, and I'll leave it.
I've been working on a project recently and have spent around 12+ hours a day coding, but then my leisure time is spent watching TV or playing a video game. I was curious to know how that compared to the folks in this forum.
This past week, I had a weird experience where there was a white spot in my vision that prevented me from being able to read. Any particular letter or number I focused on couldn't been seen. It only lasted for about fifteen minutes but left me with a headache that lasted a couple of hours. According to my eye-doctor, it was probably an ocular migraine.
Laptop/tablet/phone/etc. Looking for inspiration, browsing, stuff like that. I would say sometimes more time may be spent here, but it probably is also 2 hours.
TV I try to avoid. I like to watch a few teams and catch some games here and there. Mostly movie time, so another solid 2 hours in this category.
6-8 hours easily, and I always feel like I could double this and still wake up the next morning with a full checklist of things to accomplish.