Rich Units

RichUnits is a very easy to use unit system for the Ruby programming language. It is essentially the same system popularized by Ruby on Rails.


Rich Units is a straight-forward units system based-on the original time units work by Rich Kilmer (circa 2002-2004). Rich Units extends core Ruby with conveneice methods for dealing with measures. The methods work by converting those measures to a low common denominator; for instance all durations are stored in seconds.

Rich Units provides essentially the same unit system used by Ruby on Rails*. But Rich Units seeks to imporve upon this code, and provides a superset of functionality, partly derived from the Ruby Facets distribution of the same libraries. Ultimately Rich Units intent is to provide a better system than either of these large projects can provide, by virture of a dedicated development track.

*with the present exception of the timezone extensions (coming soon).


Primarily Rich Units extends Numeric. Here are some basic examples:

      require 'rich_units'

      4.days.hence    #=> Tue Apr 01 08:04:17 -0400 2008
      4.hours.ago     #=> Thu Mar 27 22:03:33 -0400 2008

      10.bytes        #=> 80

Rich Units also extends Time.

      require 'rich_units'                   #=> Fri Mar 28 08:10:40 -0400 2008    #=> Wed Mar 28 08:10:47 -0400 2012


Installing the RubyGem is of course straight forward.

      $ sudo gem install rich_units

Manual site_ruby installation is provided via Ruby Setup.

      $ tar -xvzf rich_units-0.4.0.tgz
      $ cd rich_units-0.4.0
      $ sudo setup.rb all


Repository Hosting

The project is hosted on GitHub at

Contributor Repository Access

To pull the 'richunits' repository anonymously, use:

      git clone git://

Otherwise create a fork.

Master Developer Repository Access

Developers, you can git commit access if you submit a good patch.

Only project developers have access to the main repository. Please contact transfire at if you'd like to join the development team.