The 1st of May was first marked as International Workers’ Day in 1890, when the Second International called for demonstrations.
https://www.leftarchive.ie/calendar/on-this-day/05/01/#event-6415
On This Day, 1st May
Irish Left Archive[>
"May Day Greetings", from the Irish Socialist, Communist Party of Ireland, 1982
Irish Socialist, No. 229 (1982) — Communist Party of Ireland
Irish Left Archive[>
"Magnifect May Day", from Independent Socialist, paper of the Independent Socialist Party, 1978.
Independent Socialist, May 1978 (1978) — Independent Socialist Party
Irish Left Archive[>
"May Day - Labour Day '77: Solidarity With All Political Prisoners".
Socialist Republic, from the Movement for a Socialist Republic.
Socialist Republic, April-May 1977 (1977) — Movement for a Socialist Republic
Irish Left Archive[>
In reply to this post
Some May Day publications in the archive:
"Hail May Day! Organise For Revolution!"
Red Patriot, from the Communist Party of Ireland (Marxist-Leninist), 1983.
https://www.leftarchive.ie/document/3448/
Red Patriot, Vol. 6, No.9 (1983) — Communist Party of Ireland (Marxist-Leninist)
Irish Left Archive[>