should all my calendars entries be in the cloud? trying to share calendars between 2 iphones and ipad

I have 2 iphones and an ipad. On one of the iphones the calendar entries and not showing up on anything else. I have checked all the settings and everything looks good - been a headache trying to figure out what is not set up correctly. I had this working at one point. Should I see all the calendars in icloud?