According to Wikipedia: The "mayday" procedure word was conceived as a distress call in the early 1920s by Frederick Stanley Mockford, officer-in-charge of radio at Croydon Airport, England. He had been asked to think of a word that would indicate distress and would easily be understood by all pilots and ground staff in an emergency. Since much of the air traffic at the time was between Croydon and Le Bourget Airport in Paris, he proposed the term "mayday", the phonetic equivalent of the French m'aidez ("help me") or m'aider (a short form of venez m'aider, "come [and] help me"). The term is unrelated to the holiday May Day.
Also according to Wikipedia: May Day is a public holiday in some regions, usually celebrated on 1 May or the first Monday of May. It is an ancient festival marking the first day of summer, and a current traditional spring holiday in many European cultures. Dances, singing, and cake are usually part of the festivities.
In 1889, May Day was chosen as the date for International Workers' Day by the socialists and communists of the Second International, as well as anarchists, labor activists, and leftists in general around the world, to commemorate the Haymarket affair in Chicago and the struggle for an eight-hour working day. International Workers' Day is also called "May Day", but it is a different celebration from the traditional May Day.
So those are the secular uses of “mayday" and “May Day”, but what do we do as Catholics. The month of May is traditionally dedicated to the Blessed Virgin Mary. And to begin the month, it is tradition to do a “May Crowning” of the Blessed Virgin Mary. Also, May 1 is the memorial of “St. Joseph the Worker”, the spouse of Mary. This day was chosen by Pope Pius XII in 1955 as a counterpoint to the communist International Workers' Day celebrations on May Day.
Therefore, as we begin the Month of May, let us strive to honor the Blessed Virgin Mary this month with spiritual bouquets. Let us cry out to Holy Mary and St. Joseph our own “maydays” (help me, help me, help me) in whatever distress we find ourselves. And as we labor, let us imitate them both, offering our work as done for the Lord. Maybe instead of three “maydays” we can offer three Hail Mary’s or Memorare’s” or the Angelus (traditionally done at 6am, 12noon, and 6pm) or since we are in Eastertime the traditional Regina Caeli which I will conclude with both Latin and English versions. A helpful hint, if you want to learn the Regina Caeli, it’s fun to sing the Latin as it rhymes and has a catchy little tune!
Peace,
Fr. Greg
Regina Caeli / Queen of Heaven
V. Regina caeli, laetare, alleluia. / Queen of Heaven, rejoice, alleluia.
R. Quia quem meruisti portare, alleluia. / For He whom you did merit to bear, alleluia.
V. Resurrexit, sicut dixit, alleluia. / Has risen, as he said, alleluia.
R. Ora pro nobis Deum, alleluia. / Pray for us to God, alleluia.
V. Gaude et laetare, Virgo Maria, alleluia. / Rejoice and be glad, O Virgin Mary, alleluia.
R. Quia surrexit Dominus vere, alleluia. / For the Lord has truly risen, alleluia.
Let us pray. O God, who gave joy to the world through the resurrection of Thy Son, our Lord Jesus Christ, grant we beseech Thee, that through the intercession of the Virgin Mary, His Mother, we may obtain the joys of everlasting life. Through the same Christ our Lord. Amen.