1667/1668
For 1667/1668, the key weeks and dates were:
Week 1: 17 December to 24 December, 1667
New Year 1668, Week 3: 31 December to January 7 1668
Legal New Year, Week 14: 19 March to 26 March, 1668
Note: Week 7 reads from the 28 January to the 24 of February, although Week 8 starts January 4.
Week 1668-15 to 1668-52 missing.
