Gregorian - Monday-based week with week numbers
    September 2006     
Mo     4 11 18 25   
Tu     5 12 19 26   
We     6 13 20 27   
Th     7 14 21 28   
Fr  1  8 15 22 29   
Sa  2  9 16 23 30   
Su  3 10 17 24      
   35 36 37 38 39