Unfortunately, I believe that is standard. I recall going back to when I first bought the Eris in December that the oldest event (besides recurring events) was a month earlier, in November. I did a factory reset on May 17th, and right now my oldest event is April 17.

You should be able to go to google calendar in the browser and search from there for past events, though.

 

It's only syncing 30 days in advance. This is likely done for memory reasons. I guess they consider the calendar on our phones to be more for "coming soon" events (which for me, is fine).