The Sovereign Prince's Day in Monaco
The Sovereign Prince's Day in Monaco is held on November 19. The National Monegasque Feast Day was established by Prince Charles III in 1857 to coincide with the Sovereign Prince Patron Saint’s Day, thus constituting a moveable feast. This event in the second decade of the month November is annual. 
Help us
Help us 
Monaco’s National Day is also a celebration of its independence which is just as important to Monaco as July 4th is to the Americans. It was first celebrated by Honoré III on 16th May 1734 and then in 1854, Prince Charles III changed the date to November 4th—that of his own Patron Saint. In fact, HSH Prince Albert could have chosen November 15th after his own Patron Saint. But in honour of his father Prince Rainier he kept it as November 19th.
Albert II OLY (Albert Alexandre Louis Pierre Grimaldi; born 14 March 1958) is Prince of Monaco, since 2005. He has Irish, German, and Monegasque ancestry. The Prince was a dual citizen of both the Principality of Monaco and the United States of America by birth, before renouncing his American citizenship in his early adulthood.
Similar holidays and events, festivals and interesting facts
All Saints' Day a holy day of obligation on November 1 (a national holiday in many historically Catholic countries. And its related observance: Day of the Innocents, The first day of Day of the Dead or El Dia de los Muertos celebration. - Mexico, Haiti);
Monaco National Day on November 20
Sainte Cecilia Day in Monaco on November 24 (Saint Cecilia is the Saint Patron of musicians. Her Feast is celebrated on the Sunday following Monaco’s National Holiday);
St Nicholas Day on December 6 (International. The St. Nicholas/Santa Claus leaves little presents in children's shoesl);
U Pan de Natale in Monaco on December 24 (The Committee for the preservation of Monaco’s Traditions requests all bakers to sell « U Pan de Natale », Monaco’s Traditional Christmas Bread);
Festival Internazionale del circo di Montecarlo on January 17 (Usually held in December);
Devota in Monaco on January 27 (Christian feast day. Feast of Sainte Devote, Saint Patron of Monaco and of the Prince’s family)