They also celebrate the Day of the whiner - a holiday of support for those who are overly upset. Bulgaria celebrates Father's Day, and the USA celebrates Sugar Cane Day.
December 26 went down in history thanks to the following famous events:

Pierre and Marie Curie discovered the radioactive element radium in 1898.
in 1918, the restoration of the UNR was proclaimed and the government of the state was formed - the Council of People's Ministers of the UNR
In 1963, the Beatles' first single "I Want to Hold Your Hand / I Saw Her Standing There" was released in the USA, which on February 1 of the following year went to first place in the American hit parade, the "British invasion" of Beatlemania began in the USA.

in 1974, the USSR finally allowed the issuance of passports to rural residents
in 1991, the Council of the Republics of the Supreme Soviet of the USSR held its last meeting and adopted a declaration, which stated the fact of the cessation of the existence of the Soviet Union.
CHURCH HOLIDAYS
On December 26, Orthodox Christians commemorate the holy martyrs Eustratius, Auxentius, Eugene, Mardarius and Orestes. All of them suffered for Christ in Armenia during the reign of the Roman emperor Diocletian.

FOLK SIGNS
If on a clear day paws and needles of frost appear, expect a sharp cold snap and a snowstorm.
What is the weather on December 26, so will January be.
If it is very sunny on December 26, then in the following days the weather will be frosty and clear.
If magpies are jumping in the snow, it means that soon it is worth waiting for warming.
The stars are bright December 26 - expect frost.
WHAT NOT TO DO ON THIS DAY
You can’t swear, because a witch can fall on your head.
Also, you should not leave a broom on the threshold so that evil spirits do not steal it.
You can’t harness a white horse to a sleigh so as not to bring the dead home.
You should not wish evil to someone on this day, so that what you want does not fly to you.
WHO HAS AN ANGEL DAY
On December 26, Angel Day is celebrated by: Arkady, Arseny, Eugene, Orest, Anastasia.