And that's it. If you did not know the name of it now you do.
Clueless people always saying "just get up early and at night you will be tired"
If you have "Delayed sleep phase disorder" Are a night owl like me you know how irritating it is when people say that and that it never works. Get up early for a week and maybe you fall asleep early one night then its back to being awake till 3 am till you suffer 5 more early wake ups and are tired and fall asleep early once then it resets.