update

Today I updated my s3 and now all my calendar entries are gone. How do I recover them

The Samsung calendar?

yes

I don't know if that data can be recovered. Have you tried installing Google calendar? Maybe Samsung was set to upload to that.

Signed, a Nexus 5, AC forums app, and Android L.

The update was the android update to 4.4.2

Try syncing your Samsung account (not Google). Master Sync on - General - Accounts - Samsung Account - touch account name - Sync Calendar. It would need to have synced before the update obviously, but it may have done.
Just a shot.

no luck

- - - Updated - - -

I installed google calendar and it did not help.

.... and you never synced or backed up to Kies on a pc.