I believe that's referring to the calendar change about that time that added eleven days, to rectify "equinox creep" that happened before astronomers realized that 365.25 was not the exact number of days in a year. It was corrected by having leap year be observed on even-century years ONLY if they were divisible by 400, as opposed to all other years which require being divisible by 4. The accumulated error also had to be corrected, though, hence the eleven-day jump forward.

As you can imagine, arbitrarily skipping eleven days like that caused all kinds of problems, and not everyone took the change graciously. The old and the new calendars ran side by side for a while in different localities, sometimes adjacent geographically but eleven days apart.

Edit: You beat, by five minutes So where's the button that says "A new post has been added to this thread since you looked last - you may wish to check before you post!"

Last edited by wofahulicodoc; 10/08/2005 12:14 AM.