You can share your Outlook calendar with anyone who has an email address, even if they don't use Outlook.
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How to share your calendar in Outlook

When you need to set up an appointment or meeting, one of the first things you do is look at your calendar. Sharing your ...
If you encountered an issue where the Outlook shared calendar disappears after a restart, don’t feel like you are alone. This is a known issue affecting many users, particularly in desktop versions of ...
Imagine this: You’re coordinating a critical meeting with team members spread across New York, London, and Tokyo. You double-check the time, only to realize you’ve accidentally scheduled it during ...
You can unshare your Outlook calendar if you want to remove someone from a previously shared calendar.