What is the publication date of the play The Importance of Being Earnest?
The play was first performed in the year 1895 (St. James Thetre, London). The play was published in book form in the year 1899. All of these are the three act version of the play (as the play is known now). Wilde however originally wrote the play in four acts and later condensed it according to the requirement of the producer of the play, George Alexander. This four-act version was published in 1956.
Athough the play was first produced in 1895, I believe the first time the play was actually published was in 1908 by Methuen Press in a full collection of Wilde's works (The Collected Works of Oscar Wilde). Robert Ross, Wilde's good friend, edited the collection. The scandal of his trial kept the play out of print until after his death.
The original publication date is 1895. It was first performed on Saint Valentine's Day in 1895 in London.