Slack has released a new feature that allows the users to alert other users that are online at that time.
Earlier, when the users sent a message in a Slack channel to @everyone would bring them a warning that they were about to fire out a notification across time zones that might wake some people up.
According to thenextweb.com, the users by typing '@here' before their message will notify team members who are active and leaving people who might be in sleep.