I didn’t know this used FullCalendar. I’ve actually worked with that extensively. I did a major integration with a custom CMS. I’ve also spoken with the creator Adam Shaw (a freaking genius this guy) on a few occasions and provided some massive blocks of code for feature updates like a full screen mode, hover tool-tips with event details and an undo option (small box that appeared on bottom right after deleting, etc.). That was almost 2 years ago. I think it was v1.4.x and it’s up to v1.5 now I think.
Actually, I’m using Adam’s “TI” (Template Inheritance) PHP code in the Salutation framework