What time is it appropriate to message someone?

To avoid waking someone up, dont text too early or late. “The rule is 7am to 9pm, but if you know the person well, you can probably push that range out a little bit,” says Post Senning.

When should I send him a message?

Many people will advise you to wait a bit to text him after your date. Some people will even tell you to wait for him to text you first. In these modern times, you do not have to wait for him to text first if that is not what you want. You should not feel weird about reaching out to him first after your date.