calendar not syncing

[twistedfish]

I am an IT guy and I have seen this on a regular basis (at least a dozen times) on both my phone and other users phones. Typically I have found there is an app that is access the calendar that probably never should have in the first place, but on a rare occasion I have found corrupt calendar items that will cause the issue.

I would recommend you remove your account from the phone and then reset it up (your email account that is tied to your calendar). 9 out of 10 times this will resolve the issues that I have seen, beyond that reseting the phone to factory defaults and starting over is the other option.