19:41
Yes, but that logic is quite "behind the times". Social media has turned out rather intrusive overall, and most people have adopted a new logic - even chats shouldn't come with a demand of "I expect you to reply immediately". That's still reserved for phone calls!
So, I keep to the rule that even social media "chats" can take place one message at a time, slowly, even over days. I think that's the standard these days, and certainly how the chats in Mi Yodeya are generally utilized
So, the nakfa mina of chats is there is no limit to how much we can talk, that's all. We are not being moderated beyond civility