Stylesheet Query String

How does Rails come up with the query string appended to the stylesheet tag?

The API does not even show a query string being appended: http://api.rubyonrails.com/classes/ActionView/Helpers/AssetTagHelper.html#M001499

I thought it was a function of the file timestamp, but I have updated the file and the querystring still hasn't changed. I just don't want my users to have to refresh to force their browser to see the new stylesheet.

Thanks! Tom

I never saw a reply to this post? Is my question hard or dumb? :slight_smile: