Native Data class in Ruby 1.8 is much slower than Date::Performance – class Data, partially re-written to C

http://blog.pluron.com/2009/04/ruby-date-class.html
https://github.com/rtomayko/date-performance

Unfortunately, it is for 1.8 only. It will not compile on 1.9

rtomayko commented

January 15, 2010
Oh, now that I think about it, it's going to take a lot of work to get date-performance running under 1.9. They've changed a ton of stuff with Date. I'm not sure when/if I'll get around to it.
This may be a 1.8.x only library unless someone wants to take a crack at porting to 1.9.

https://github.com/rtomayko/date-performance/issues/1#issuecomment-110638