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

Please notice the comment from Damian Nowak. These commands do possibly mess up your rubygems!

On Ubuntu 11.10 the following solved this error:

sudo gem install rubygems-update
sudo update_rubygems     

The following may work on some systems but not on Debian based:

sudo gem update --system