Calculate the ideal time to go to sleep based on the time you have to get up tomorrow.
In your sleep you go through different stages of the sleep cycle. When you wake up in the middle of your deep sleep, you feel less rested.
1. On the Sleepytime website you can calculate what time you should sleep based on the time you have to get up. You have to be able to estimate for yourself how much time you need to fall asleep.
2. Some activity trackers, such as some Fitbit models, have a smart alarm clock. The strap keeps track of whether and when you sleep based on your movements. You can set the times between which you want to wake up, the strap will wake you up at the ideal time.