Oronce Finé was born on 20th December, 1494 in Briançon. Benjamin Roussel was born on 20th December, 1796 in Saint-Nicolas d'Aliermont. Jean-François-Eugène Denis was born on 20th December, 1806 in Saint-Nicolas d'Aliermont. Léon-Pierre Boé was born on 20th December, 1814 in Saint-Nicolas d'Aliermont. Athanais-Lucile Cailly was born on 20th December, 1840 in Saint-Nicolas d'Aliermont. Jules-César Huguenin (Virchaux) was born on 20th December, 1840 in Le Locle. Léon-Alexis Ropert was born on 20th December, 1842 in Dieppe (Seine-Maritime). Fritz Ulysse Ducommun was born on 20th December, 1862 in Brot-Dessus near Les Ponts-de-Martel.
Guillaume Delépine died on 20th December, 1791 in Saint-Nicolas d'Aliermont. Pierre Michel Lepaute died on 20th December, 1849 in Paris. Charles-Félicien Tissot died on 20th December, 1873 in Le Locle. Carl Lorenz died on 20th December, 1889 in Berlin. Eugène François Audemars died on 20th December, 1897. Marcelle-Alexandrine Lefebvre died on 20th December, 1984 in Bagneux (Hauts-de-Seine).