forums.silverfrost.com

[simon]

It started in 1582 only in some countries. Britain adopted it only in 1752. Countries like China, Turkey, and those aligned with Russia adopted it a little over 100 years ago.

[simon]

It started in 1582 only in some countries. Britain changed in 1752. Countries like China, Turkey, and those aligned with Russia only adopted it a little over 100 years ago. I believe that in all cases days of the week were not skipped, but dates of the month were, so algorithms such as the one discussed here are location and time specific, and if you want to go back in time by more than 100 years some adjustments will be needed. You can't even make a simple adjustment by country because Alaska, for example, adopted the Gregorian calendar later than other parts of the US (because it used to be part of Russia).

[arctica]

The Wikipedia summary gives a good overview:

https://en.wikipedia.org/wiki/Gregorian_calendar

[mecej4]

Applying the DOW function to dates from decades ago can be beset by many problems. For instance, consider the Alaska problem:

the purchase date of Friday, October 6 (Julian) was followed once again by Friday, October 18 (instead of Saturday, October 19 in Gregorian)

Time zones have historical issues. Alaska had four time zones in some past years. Even now, London and Paris are one hour apart, even though Paris is just 2 degrees longitude to the East of London and, therefore, should differ by just 8 minutes of time. This was a consequence of the German occupation of Paris during WW-II.

[JohnCampbell]

You have been discussing different calendars, when they were adopted and now the problem of time zones.
However the most annoying calendar for me is Bill's Excel(ent) calendar, which provides:
Tuesday, 28 February 1900
Wednesday, 29 February 1900
Thursday, 1 March 1900
( I assume that 1-Mar-1900 was a Thursday and 28-Feb-1900 was a Wednesday ?)