Polina Shepherd says that is the song she taught just yeesterday!!!! (too bad I didn't attend her workshop this week)

https://www.polinashepherd.co.uk/sing-with-me-past/
with link to pdf song sheet in Yiddish, transliteration, English translation; and a sound recording.

A Sheyner Tog, a Frilings Tog

"A Beautiful Day, A Spring Day is the name of our today's Yiddish song - and it is Spring for lots of us in SWM! This song is also known with a title Memories (Zikorn). The composer is unknown but the lovely poem was written by Jacob Adler (1873–1973!), a poet and humorist. Adler was born in Dinov, Austria-Hungary (now Dynow, Poland) and immigrated to the US in where he worked in sweatshops, agitated for socialism and wrote nostalgic poems about the "old country". The song was popular in the 1930s in Poland. Interestingly, it was published in a songbook Mir Zingen in 1948 by the MEDEM Center, Paris, through the Union of Jewish Socialist Children.

"Source: Songs of generations: New pearls of Yiddish song., New York E.G. & Mlotek, J., 1995. and National Library of Israel."