[maroon93]

I think that is because your inner time working incorrectly and it think that night is day and vice versa day is night.
It often happen people who travel by plane for long distances to a different timezone or skipping multiple nights to work or for learn and then sleep a little in the morning or afternoon. A few month ago I had this issue too.
Here is how you can fix it: 
Skip a full night then next day go to bed at midnight, and then wake up early in the morning for example 6 am.
Next evening go to bed at 11 pm and wake up next morning at 6 am. Next evening go to bed at 10 pm, and so on. After the third or fourth night your inner clock will be back to normal working.

nice sleeping tutorial : i ll try it too. because i have bad sleeping habbit