isn't it weird?

It's your body clock. I think you should try to reschedule your sleeping habit/time. I used to be that way before when I stopped schooling. Late sleeper and wake up in the afternoon and feel lazy the whole day then regret at night for not being able to do anything for the day. So was, my older brother. What we did, we went awake for like more than 24 hours playing computer games, talking, etc. and slept early the next night, maybe 7pm. I think I woke up around 9 or 10 am, still feeling sleepy though but I fought it because I had to. I reserved my sleepiness for the night and again went to sleep early that night so by then my body clock went back to normal. Try this, and I hope it'll work for you. But maybe you'll get better suggestions from others.

Its not a bad thing until it affect your health.But humans are bound to natures and you should follow the nature rules to lead a healthy life.There is no other go.