Plugin that can convert a post into an event date

Hello!

Does anyone know of a plugin that allows an event date to be attached to a post? We post all updates through the blog and some of them are events. We'd like to put a calendar widget in the sidebar that can pull these events.

I used this plugin the past: http://wpcal.firetree.net/, but it's so outdated that it broke our site. We need an alternative solution.

Any thoughts or suggestions would be helpful!

Sinoun