Thanks! I had it in for about 4.5 hours. That wasn't as long as I had wanted to leave it in, but I didn't get it on my hair until 9pm... so it seemed like sleeping with it on would have been a bit excessive, but I also didn't want to stay up to wash it out at 3 or 4am either. =P
My boyfriend is already complaining about the henna stink just from mixing it. lol