Why does he only contact me at night?

Hey! So I’ve been talking to this guy: he contacted me first and he asked me out twice. He only texts me back at night though. When we talk at night it’s nothing sexual he’s a nice guy and it’s a wholesome conversation. I know he’s busy with work and school, but I feel like it shouldn’t take hours and hours for him to respond? He posts stories of him going to eat with friends, but doesn’t respond until hours later. Also he contacted me first so I’m just confused 😅 what’s up with this? Is it normal? Sometimes he messages during the day time and then just disappears for 4-5 hrs. I feel like if he’s busy it’s okay, but maybe a message saying he has to go would be normal? Thank you all