Madam, – A decade is a period of 10 years. It is not fixed at specific points on the timeline. Thus, each moment that passes marks the end of a year, lustrum, decade, century, millennium, etc, that began one, five, 10, 100, 1,000, etc. years ago. I (like most people I suspect), prefer to apportion greater significance to the end of a particular time period in accordance with how it affects the representation of the current date.
For this reason, 01/01/2010 is a greater end of decade event than 01/01/2011 (the former changing two digits in the year). For the same reason the 1999 to 2000 transition was far more significant than the 2000 to 2001 transition. I do not understand why certain people (for example, Stephen W Sykes, January 4th) are obsessed with the fact that year 0 didn’t exist. If these people are true to their principles, they should celebrate New Year’s Day at a date that considers all the calendrical changes since Christ’s birth – which is certainly not January 1st. – Yours, etc,