I'm a freelance programmer and one of my clients has a Slack workspace that I use to communicate with coworkers. To do my work I often need to ask questions of one or more of my coworkers, but often the person I need to talk to is not online, and I have no sense of when they are likely to be online.
Is there some built-in Slack feature or Slack add-on that would allow me to get a sense of when a person is typically online? Like showing when they've been online over the past week?