The first cycle lasts 90-100 minutes. Then the cycles are repeated with the reducing proportion of slow wave sleep and gradually increasing proportion of REM sleep, whose last episode can, in some cases, last up to 1 hour.
On average, the good quality healthy sleep includes five cycles.
Estimated time of the good quality sleep is about 7-8 hours.
In order to recall the dream, one should wake up during the REM sleep. To begin with, identify your «best morning hour».
If you go to bed at the same time, you will be able to calculate the duration of sleep, i.e. to determine what time to set the alarm-clock for to wake up during the REM sleep and to recall a dream.