By the 16th Century a sizable drift had developed between the Julian calendar, the lunar calendar, and the real moon which the new calendar sought to resolve.
21st June 1919: The German High Seas naval fleet is scuttled at Scapa Flow
21st June 2019
The Islamic calendar was dated to start with the first new moon after the Prophet Muhammad and his followers migrated to Medina.
On the 4th October 1582, Pope Gregory XIII implemented the Gregorian calendar.
HistoryPod Extra: The Myth of Gavrilo Princip’s Sandwich
28th June 2015
3rd August 1492: Christopher Columbus sets sail from Spain
3rd August 2020
1st September 1939: Nazi Germany invades Poland
1st September 2018
9th November 1989: East Germany opens the Berlin Wall
9th November 2019