baby sleep

What time po natutulog ang 4 month old lo nio? Mine is midnight! Kahit 0630 am ko sya gisingin, natutulog sya sa daytime ng marame para he is still up hanggang midnight. Which is definitely not good for his brain development. I enforced sleep trainings pero he sleeps at daytime like 4 hrs of sleep sa isang nap. Paano po ang sleep routine nio? I really want na maayis ang sleep nia..