why doesn't iOS calendar show all events?

My desktop, running Mavericks, shows events in my Calendar going back for months. My login to icloud.com does the same. But on my iPad, iOS 7.0.6 does not. It goes back about 35 days. I've tried settings on the iPad, desktop, everywhere I can find. I have the Calendar settings on the iPad set to All Events. I've rebooted, sync'd. What else should I look at? Or, is this a known bug? Thanks!