iPad icloud calendar not syncing to iPhone 4s

I have setup iCloud on my iPad 2 and that works perfect. After I buy a new iPhone 4s, I have the iCloud on in the device. The contacts merge fine, but iPad does not sync with iPhone icloud calendar. When I make a change from my iPad, the calendar won't show up on my iPhone. When I make a change on the phone, it will show on the tablet. I can't figure out how to fix the issue.If you have the same