Invalid gemspec because of the date format in specification

Question

When I include a gem that I made, thanks to Bundler (version 1.0.12), in a Gemfile and then I try to bundle or to rake just like that:

$ rake

I\

Answer 1

Even if you install the latest version of a gem with a valid date format, make sure to gem cleanup GEMNAME afterwards, since gem will still complain about the specifications for the older libraries.