How do I know when is My REM Time?

I'm now trying out WILD and after reading up some tutorials and asking a bunch, this question still lingers around. How do I know when is My REM Time? Is it different for everyone or is there a fixed timing? I still remember that when I tried to WILD the 2nd time ( Maybe 2nd is the charm (First didn't succeed)) I saw pitch black and had this adrenaline exciting sensation, while being "not able to move". My friend told me it was the stopping of NREM, so I the main question is that How do I know when is my REM Time?

P.S (Sorry for being such a chatterbox xD)

Just practice. Most people the ideal time is after 4-6 hours of sleep.

It mainly depends on how long your sleep cycle is. As you sleep, you go through the different stages of sleep, from stage 1 to stage 4, followed by REM sleep, which repeats every 60-120 minutes (90 minutes on average). However, it varies for each person.

http://upload.wikimedia.org/wikipedi...eep_Phases.jpg

As you can see, the amount of REM sleep (the red lines at stage 1) get longer after each sleep cycle, which is why waiting 4-6 hour is best, since after 3-4 cycles, your REM stage is longer than in the first stage. However, it's hard to nail down a specific time, as like I said earlier, sleep cycles are different for each person.

But like ThreeCat said, it just take practice. Start with 4.5 hours, and if that doesn't work, try tweaking it a little.