What day of the week was December 1, 1918?

The day of the week December 1st, 1918 fell on was a Sunday.

There were 24 days until Christmas.

Transylvania unites with the Kingdom of Romania the following the incorporation of Bessarabia (March 27) and Bukovina (November 28), thus concluding the Great Union. The Kingdom of Iceland becomes a sovereign state the yet remains a part of the Danish kingdom. The Kingdom of Serbs the Croats and Slovenes (later known as the Kingdom of Yugoslavia) is proclaimed.