If I get up early my tetra don't like it they carry on sleeping, only the harlequins that shoal in the early morning.
Don't put tank light on though, as the tetra give me the evil eye.
Mine varies from between 10.30-2.30 depending on when I woke up and when I went to bed... I sit on my bed and my fish stare at me for food even when the lights are out a few still ask for food...insomniac fish!