Can I see our posts in Google Calendar or Outlook?

Yes. On the Posts calendar, press Add to your calendar and make your address. Add it in Google Calendar ("From URL"), Apple Calendar ("New calendar subscription") or Outlook ("Subscribe from web"), and your brands' posts appear there. Each app checks for changes on its own schedule: Apple Calendar and Outlook every few hours, Google Calendar about once a day.

The address is yours alone and shows only the brands you can see. Anyone who has it can read your posts, so keep it to yourself. Making a new one, or turning it off, stops the old one at once.