"Whisper"/ Muted Messages

so as you may know, people live in different time zones and sometimes are asleep while your awake. so lets say I want to contact someone and don't want to wake them up from a ping or notification on their device (this happens to me a lot). So I was thinking maybe a good way to do this is to add a way to message someone without sending a ping noise or a notification, so when they do wake up, they only see 1 discord notification image but it doesn't make any noise, so they still know they've been texted. I was thinking it could be called like "whisper messaging" or something like that.