The timing of sleep is very individual. Some people are natural night owls, and, if their lives allowed, would be best going to bed at 2am and waking at 10am. Others are early risers, best at 10pm and waking at six. And those are only examples.
Others do well with shorter night sleeps and cat naps. My own natural rhythm is to go to bed early (say 9), sleep four hours, wake for two and do wonderful creative work, then go back to bed for four more.
These rhythms also change for each person with age and illness.
Connecting with ourselves and coming to know our own natural rhythm is most important. Of course, sometimes, we must adjust our rhythm to meet the demands of job and children and such.
As far as how to get 8 hours of sleep, taking any medication is, for most people, not a good idea. Instead:
- for 2-3 hours before bed, take in no news, and nothing stressful or violent
- learn to breath and relax with meditation or gentle exercise.
- do not use caffeine after noon
- if possible spend some time in a natural environment. If not, make your home or bedroom soothing and pleasant.
Then sleep will come naturally.
If, after all these techniques, sleep does not come naturally, then many natural remedies are available.