Feedings for baby- formula fed

LO is 7 weeks old. Should I be feeding more during the day so he can sleep more thru the night ? Or feed more thru the night and less thru the day. Would love to know what everyone is doing. He eats 2.5 oz during the day. Night time feedings he does 3 oz. He was born at 36 weeks so we had to start off slow. He falls asleep about 9:30. Wakes up and feed about 1:45. Falls asleep. Wakes up about 4:30. Eats and falls asleep. And wakes up at 6:30 grunting and snorting due to reflux. I have to pick him up and sleep him back on my chest until 8:30 or 9.