January 1st 1600 is sunday, not monday!

It's saturday, not sunday!

here's the answer for 1 1 1600

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