For what it’s worth, I read many years ago that when the world was approaching the year 1,000 the calendar makers refused to make any new calendars because it would be the end of the world.
More to the point, the darned “fossil fuel” complainers will go to any end to ignore weather history and go on making money off of people’s fear.
“... the calendar makers refused to make any new calendars...”
What ‘calendar makers’?
Wood block printing did not show up in Europe until the 1300’s or so. Johannes Gutenberg did not invent the printing press until 1439.I doubt that a scribe would spend the time writing a calendar unless he had a contract.
The Chinese & Arabs used different calendars, neither having dates anywhere near 1000.