27 March 2007
A succession of five years beginning and ending in a leap year will advance the calendar by exactly one week, and so in such a succession, dates on the first and last year of the succession will fall on the same day of the week. This is because a leap year advances the date two week-days. Two leaps years plus four normal intervening years equals seven days. Oh, all right, I will spare you the remainder of the calculations. Suffice it to say that Christmas Eve fell on a Sunday in 1995, again in 2000, and again in 2006. The next time this will happen will be in 2017, and then in 2023, and so on in a repeating pattern of 5, 6, 11, and 6 year intervals. That 5 + 6 + 11 + 6 = the number of years in a leap year cycle times the number of days in a week is not accidental, and the wiseacres amongst you may like to point out that the pattern will be messed when passing 2100, 2200, and 2300, but not across 2400 – but I don’t care! Huh? Oh, you were wondering what this had to do with Christmas. You weren’t? Well, you should have been. Only that it was on Christmas Eve, Sunday the 24th of December, 1995 that we (except Johnny, who was in Seattle by then) were received into the Catholic Church, so this year Christmas Eve was the 11th anniversary of that to-us momentous event. This coincidence will not recur for another 11 years. Oh, yes, so what, indeed! But I thought it was amusing to do the maths. Johnny came over from Sydney on the 21st and we had a wonderful 11 days (there’s that number again!) with him, doing lots of things (too many, he and we sometimes thought). On Christmas Day we went up to Eddie’s and Eveline’s house in Helensville. On Thursday the 28th we drove down to Paeroa (world famous in New Zealand - http://www.lp.co.nz/home.htm) to see Radiant Rachel. That’s a family code and Johnny’s siblings will know who I mean. Johnny tracked her down and she is a mother now. On Saturday the 30th we went to the Franklin Zoo and generally had fun whilst he was here.