main=(putStr . unlines) (f 3 c)
c=[31,29,31,30,31,30,31,31,30,31,30,31]
s n|n<10=" "++show n
s n=show n
g []=[]
g x=let(a,b)=splitAt 7 x in (' ':unwords a):g b
f n []=[]
f n(x:xs)=g m++("":f (mod (length m) 7) xs)where m=replicate n" "++map s[1..x]
Note that non-ascii characters in the above source code will be escaped (such as \x9f).