I have a iPad mini IOS 8.0.2 and a iPhone 5S IOS 8.0.2
I was having the same issues.
I just did a reset on both devices.
Hold down the power button on the top and hold down the circle on the bottom at the same time. Wait for the screen to go blank and for the apple to come back. This will reset the device. I did this to both devices.
I then went into my email added and event to my calendar from my iPhone and then I checked my iPad Mini and there it was.