There were 7883 days between 18 November 1918, when Latvia was first founded, and the Soviet occupation on 17 June 1940. Thursday, 21st of March, it was 7884 days since Latvia regained its independence. One day counts.
To commemorate this fact, several events took place in the center of Riga, including the speech by the Minister of Defence of Latvia, Artis Pabriks. He calls the 21st of March ‘Latvia’s Freedom Day’ when every citizen should appreciate the joy resulting from different freedoms, namely, the freedom of association, movement, thought, expression, and belief.
Source: http://www.apollo.lv/zinas/latvija-sasniedz-ilgako-neatkaribas-periodu-pastavesanas-vesture/559357