Events are a type of registry that exists as an activity. Activities have 2 types of sharing defaults, “Private” or “Controlled by the Parent”. This is important because Activities does not have sharing rules.

There is one workaround. By making the Activities sharing “Controlled By Parent” if our user has access to the Event’s Parent(Which is an account) he will gain access to that accounts events

So here is what we are going to do:

Step 1:

• Create a dummy account, it can be named anything. Just make sure your users know its purpose so adding that to its description or having a clear name are very recommended

Step 2:

• Go to setup and type sharing, click on Sharing Settings
• On OWD click on edit
• Change the Activities setting to “Controlled by The Parent”
• Click save

Step 3:

• Stay on the Sharing Settings
• Scroll a little bit to find the Account Sharing rules
• Click on “New”
• Give the new rule a name, label and Description
• For the type pick “Based on criteria”
• In the criteria make it like this: “Account Name: Equals: Dummy Account Name(this is the account we made earlier)
• Now pick who should see your data, it could be an user, a role or a group
• Give the appropriate access, it should be at least “Read Only”
• Click Save

Now make sure that the events you want to make visible have your dummy account as their related too