#!ruby -pa
t=Time.gm$F[1],$_
$><<t.strftime("%B %Y").center(20)+"
Su Mo Tu We Th Fr Sa
%#{2+3*t.wday}d"%1
$_=$/*6
$><<[t.wday>0?" ":$/%chop,"%2d"%D]while 1<D=(t+=87e3).day
Note that non-ascii characters in the above source code will be escaped (such as \x9f).