You can allow your calendar to be seen by others with Exchange. They have to open your calendar on their computers, however to see this. Learn how at "Open a shared calendar," in the next section.
The Reviewer level allows the user to read your items, view your calendar folder, but they cannot edit or delete items. Click OK when you have finished setting the desired permissions. The new user can now open your calendar as a shared calendar.
Note: You might also want to set the Default user to Reviewer if you have a lot of users who would need to view your calendar.