Rapidshare Happy Hours.. Is it has a schedule?

Hi... this is cool, This day I often met the Rapidshare Happy Hours. Althougt your allowed download is always one (at free download), at least you are no need too insert any code as usuall..
I found it (RHHs) twice this day, and it would be nice if that has a pattern or like a schedule.. :-D

this what I met :