Shachar Lovett and Sasha Kulikov created a website for TCS events, at http://cstheory-events.org. There is also a link to the site from the the top-level menu at Theory Matters.
From the creators:
The goal of this website is to allow the TCS community to advertise and learn about relevant events (workshops, schools, etc), with a focus on algorithms and complexity. We added the top theory conferences for convenience, but the goal is to mainly focus on events that do not repeat annually and that people may not be aware of them.