site.btaObservances: May 15

The world:

International Day of Families. Marked by a decision of the UN  General Assembly as of 1994.

On this date in Bulgarian history:

1879: Prince Alexander Bogoridi steps in as Governor General of Eastern Rumelia. Remains in office until 1884.

1892: Stoyan Mihaylovski writes the "Cyril and Methodius" poem, which later serves as the lyrics of the "Vurvi, Narode Vuzrodeni" anthem, also known as the Anthem of Bulgarian Education. It is first performed solemnly in Lovech on May 24, 1901.

1942: Institute of the Bulgarian Language with the Bulgarian Academy of Sciences established.

1976: Diplomatic relations established with the Gabonese Republic.

2006: Bulgaria's first waste separation installation unveiled in Sliven.

2007: Bulgarian-Russian dosimeter Liulin 5 installed on board the Progress 25 cargo spacecraft as part of the International Space Station international space experiment for radiation research.