Iphone Calander

Is there a way to have your iPhone Calendar or your eM Client calendar sync back and forth? So if you update one, it updates the other?

It is probably an iCloud Calendar. You can add that by going to Menu > Tools > Accounts and adding a new account. Choose Calendar > iCloud Calendar.

When that is all setup, make sure you save new events to the correct calendar by clicking on the folder at the bottom of the new event dialogue before saving. Any events saved to the iCloud Calendar will sync to other devices that are connected to the same account.