Johann Heinrich Seyffert was born on 7th September, 1751. Abraham Daniel LeCoultre was born on 7th September, 1762 in Le Chenit. Pierre-Adrien Delaporte was born on 7th September, 1768 in La Chaussée (Seine-Maritime). Ismérie-Albertine Sellier was born on 7th September, 1849 in Saint-Nicolas d'Aliermont. Alfred David Louis Adolphe Nicole was born on 7th September, 1850 in Le Chenit. Sophie-Marie Roussel was born on 7th September, 1852 in Dampierre. Auguste-Napoléon Letournelle was born on 7th September, 1859 in Saint-Nicolas d'Aliermont. Berthe-Ëmilie Letournelle was born on 7th September, 1859 in Saint-Nicolas d'Aliermont. Achille Ernest LeCoultre was born on 7th September, 1901 in Le Chenit.
Denis Miroglio died on 7th September, 1704 in Geneva. Jacob Miroglio died on 7th September, 1704 in Geneva. Eugène Constant LeCoultre died on 7th September, 1882 in Le Petit-Saconnex, Geneva. Jean Etienne Dufour died on 7th September, 1893 in Yverdon. Hippolyte Parrenin died on 7th September, 1915 in Villers-le-Lac. Jules Henri LeCoultre died on 7th September, 1931 in Le Lieu, Vaud.