The answer for "30 1 2012":

mon........2....9...16...23..[30]
tue........3...10...17...24...31
wed........4...11...18...25.....
thu........5...12...19...26.....
fri........6...13...20...27.....
sat........7...14...21...28.....
sun...1....8...15...22...29.....

between first and second column there are exactly 4(!) '.';