site.btaObservances: August 13

The world:

- International Left-Handers' Day (designated by Left Handers International, first observed in 1976).

On this date in Bulgarian history:

- 1888: Sofia Railway Station and railway from Tsaribrod to Sofia are inaugurated (old style date: August 1, 1888). Orient Express, international train from London via Paris to Constantinople, arrives in Sofia.
 - 1912: First flight performed by Simeon Petrov, Bulgarian trained at Louis Bleriot's school in France. Petrov flies Bleriot XXI airplane.
 - 1992: Diplomatic relations established with Croatia.
 - 1996: Central Depository is established to provide custodial services for securities.
 - 2003: International agreement establishing Strymon-Strouma Euroregion, comprising Bulgarian Region of Blagoevgrad and Greek Prefecture of Serres, is signed in southwestern town of Blagoevgrad.