I think any bit of factors may affect the time it requires. Stress, exercise that day, or anything. I imagine it works like going to sleep. If you're tired, you'll go right to sleep. If your body is ready to rest, and your mind is not, your body will fall asleep. But what WILD is is keeping your mind active while your body makes a transition from wake to rest. Suddenly, you come to realize that your body is at rest everywhere except in your head.

That said because you don't need to worry about time. It's just a process you can choose to go through. If you're trying to focus on it enough to worry about time, it's going to take you a lot of effort and more time to gain composure enough to complete stages 5 and 6. I'd just get the sleep and wait for a more relaxed day.