NEW YORK (AP) _ ''The Time of Your Life,'' the play that won William Saroyan the Pulitzer Prize for drama in 1939, is a reassuring play, a good one to see the week before Christmas.

The Mirror Repertory Company revival opened Wednesday in the off-Broadway theater at St. Peter's Church.

There is a remarkable cast of 27 in this production, recreating the texture of city life as they come and go from Nick's Saloon in an unfashionable part of San Francisco in 1939.

''The Time of Your Life'' is playing in New York during the same season as ''The Iceman Cometh,'' which also is set in a saloon.

However, Joe, the ''master of ceremonies'' in the Saroyan play, is the opposite of Hickey in ''Iceman.'' Joe encourages people to dream, and he believes in happy endings. A prostitute in ''The Time of Your Life'' really can get married and the audience can believe it will be a happy marriage.

Mason Adams, who was Charlie Hume in TV's ''Lou Grant'' for five years, plays Joe. He has a ''radio voice,'' which is just right for the part. When radio played drama, the voices not only had to convey all the acting but they had to convey that something unknown was to come.

Joe, more than anyone else in the play, is mysterious. He could be some kind of unworldly being, one who knows the future and can predict which horses will win races; that could be the source of the money he has even though he doesn't work.

Tovah Feldshuh was wonderful as Kitty, the prostitute lonely for her dead and scattered relatives. Francois de la Giroday was touching as Joe's somewhat dimwitted gofer, Tom, who is to marry Kitty.

Tom Brennan almost steals the show as a prospector full of tall tales. Elizabeth Franz made a tiny role shine with vitality as a society woman who insisted her husband take her slumming.

Loni Berry is a terrific pianist. Gabriel Barre throws himself into comedy routines with total commitment and also can dance. Michael DiGioia as the newsboy unrolled a loud but true Irish tenor.

Peter Mark Schifter directed and James Tilton designed the bar, with vintage pinball machine and jukebox.

Saroyan makes a few social points in the play, which touches on a dock strike and the beating of few people by the head of the vice squad.

However, the playwright makes them in a quiet voice. People have the time of their lives in Nick's saloon. And so does the audience.