Any user's calendar can be posted privately or to any shared channel. Users can set custom reminders before events and get a daily digest each morning along with a weekly digest on the schedule of their choosing.
So, if a company has a shared calendar for the marketing team, for instance, Slack can send reminders to the #marketing channel 15 minutes before every weekly status meeting. If a user has a one-on-one meeting with the boss every Tuesday, that person's personal daily calendar reminder in @slackbot can help ensure that he or she won't show up unprepared.
A companywide birthday calendar could even be auto-posted in the #office channel to keep the festivities rolling, Slack pointed out.
To combine Google Calendar and Slack, users simply choose the Google Calendar option on their team's Integrations page and connect one or more Google accounts. Next, they pick which Slack channel they'd like Google Calendar to post to. Default event reminders can be adjusted or disabled, as can Calendar updates in general.
Once configured, calendar messages will appear in channels at the specified times; team members can interact with them directly by expanding or following links to Google Calendar event pages for additional options.