How long does it take to quit smoking?

I know each person is different, but about how long does it take for the cravings to go away. I can restraint from a cigarette for 8 hours each day at work, and have gone as long as 12 hours when I was on a trip with students. However, the minute the opportunity arises I’m having a cigarette. I crave the act of smoking much more than the nicotine I recieve from it (nicotine gum makes me crave a cigarette). I’ve tried to quit unsuccessfully and find if I don’t have access to them, the nicotine cravings occur about every 4-6 hours while the craving for a cigarette occurs ever 15-30 minutes. How long would it take for these cravings to disappear?

If you don’t understand the difference between craving a cigarette and craving the nicotine I don’t really know how to explain it to a non-smoker. Sorry.