Pro-tip: If you're a boss or manager, don't send email, Slacks, etc, outside of business hours. You might not intend them to be responded to until start of work, but it send a subtile message of "I'm working at 11pm or on the weekend, why aren't you?"
@grumpygamer I love the scheduled messages feature in Slack for this purpose. If I happen to be working after hours, or just think of something I don't want to forget, I can schedule the message for a reasonable time and avoid creating those subtle implications. I'll also set my Slack status to Away if I happen to be online after hours—I don't want people to feel pressured by my green bubble if it's 10pm.