Opening night

A premiere or première is the (first public presentation) of a play, film, dance, or musical composition.

A work will often have many premières: a world première (the first time it is shown anywhere in the world) and its first presentation in each country. When a work originates in a country that speaks a different language from that in which it is receiving its national or international première, it is possible to have two premières for the same work in the same country—for example, the play The Maids by the French dramatist Jean Genet received its British première (which also happened to be its world première) in 1952, in a production given in the French language. Four years later, it was staged again, this time in English, which was its English-language première in Britain.

Raymond F. Betts attributes the introduction of the film premiere to Sid Grauman.

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Wikipedia