In this completely hypothetical situation, you have a convo with someone from 3:30pm - 5pm.
At what time do you wait until before texting them again?

Whenever you want? Tf

At night or the following day but this just depends on the other person, if they enjoy talking to you they won't get mad at the time you text them.

just do it gurl, there is no time limit to when you should text someone! if you miss that person or want to start a conversation, just do it!

If you want to talk to someone, don't pussyfoot around. Talk to them. If they ignore you, ask them if you are annoying them, if they reply with something suspicious/salty, move on. I've learnt to see if people are interested early on, don't kid yourself.

It doesn't even matter lol

As soon as you want. If you don't keep their attention, someone else might.