Probably a day or two at most.
I listen to my i-pod mainly when I'm traveling to and from work, and when I'm going to bed. Music helps me prepare for the hustle and bustle of a busy day, and helps me unwind on my way back home. As for going to bed, I fall asleep much quicker if I'm listening to music. If I try to fall asleep without it, I have a million thoughts flying past me that makes it very hard to just slip away since my mind is constantly buzzing. If I'm listening to music, my mind can focus on one thing, and I'm not laying awake contemplating the mysteries of the universe or my next story idea.