Can Year Headers group events under Decades instead?

[mrsingleton]

This timeline tool is amazing, it's almost perfect but I hope there's a way to adjust one crucial aspect so it'll be even more useful for storytelling. The "year" headers ought to communicate more than the year if, for instance, I want to show events that occur every few years, decades or centuries. It would be tremendous if I could have alternate ways of labeling the headers.

I attempted to layout a timeline of certain election day results only to discover that many of my boxes won't alternate sides, most just stack on the left side because the headers occur too frequently (which makes the page longer than it has to be).

Is it possible to make headers group events under decades instead of years?

Please let me know your thinking on this.

Here's my attempt:
http://seezie.com/tests/dataviz/electoral_timeline/

Malik