It is acceptable to be ignorant in the world outside that of science, a simple look around is all it takes to see how many things attest to that notion.
On the other hand, those who work in the realm of science, and especially computer science, are expected to be a bit more rigorous in their dealings with the world around them.
One of the first things people learn in any scientific endeavor is that precision is extremely important. It is important in observation, in reporting information, in every aspect of what is done.
It would seem that some of these people who move in the circles of science should have picked that up, for they would have had enough exposure to the idea that precision is needed to convey the correct information and ideas. Perhaps not.
As the title says, there was no year zero, and since the word decade comes from the root deca- meaning ten, we should make every effort to use the concepts correctly.
Though many wish to assign cardinal numbers to years, we soon see that, at the extremes, the use of them causes loss of time, and other difficulties. Therefore, the the use of ordinal numbers, as was originally the way is the better and more correct method.
2000 was not the first year of the third millennium on the current calendar, it was the last year of the second millennium. It was likewise not the first year of the current decade, nor is 2010 the beginning of a new decade, as we currently reckon things.
The original method of counting years was ordinal, whether 1st year A.D. or regnal 10th year of King Henry VIII. This ordinal numbering is still present in the names of the millennia and centuries, for example 1st Millennium or the 20th century, and sometimes in the names of decades, e.g. 1st decade of the 21st century.
Rant off. (Remember, there is a difference between precise and pedantic.)
§
•