all my calendars in one place
All My Calendars in One Place: One Calendar for Multiple Accounts
A practical guide to keeping all calendars in one place when appointments are spread across multiple Google and Outlook accounts.
One view is not the same as one reliable calendar
Seeing all calendars in one interface helps you plan your own day. But if other people schedule against only one of those calendars, they still do not see your full availability.
The hub calendar approach
Choose the calendar connected to your scheduling links, your workplace, or your most-used account. Then copy the important time blocks from other accounts into it.
What the hub should show
The hub should show enough information to avoid conflicts. For private appointments, that can be just Busy. For work or project calendars, it can include a prefix and title.