Past release dates of various Distros

Hi all,

Does anyone know where I might find the release dates for past distributions.

For example: I need to know what the original release date was for RedHat 6.0.

This is just one example. I have several other distros that I need this
info for.

I poked around the RedHat site, but couldn't find a release time table.
Ideally, if anyone could point me to a site that would have this
information for all distros, that would be great.

Thanks,
Peter