Gregorian - Sunday-based year with weeks
   January 2147483646  
   Su Mo Tu We Th Fr Sa
 1     1  2  3  4  5  6
 2  7  8  9 10 11 12 13
 3 14 15 16 17 18 19 20
 4 21 22 23 24 25 26 27
 5 28 29 30 31