[tz] Encoding of workweek/weekend available?

Is there any public database similar to tzdata encoding workweek/weekend transitions over time? http://en.wikipedia.org/wiki/Workweek_and_weekend I am asking the folks on this list because the transitions sound eerily like DST transitions: "The coalition government formed on December 2011 issued a decree changing the weekend in Yemen. As of February 2012 the weekend in Yemen will be Friday–Saturday [instead of Thursday–Friday]." -Andrew