Anyone acquainted with Ireland knows that the morning of St. Patrick's Day consists of the night of the seventeenth of March flavored strongly with the morning of the eighteenth.

This anonymous witticism trades on a long-standing association between St. Patrick’s Day (March 17) and convivial, often alcohol-fueled celebration in Ireland and in Irish communities abroad. By describing “the morning” of the feast as essentially an extension of the previous night, it evokes the holiday’s reputation for late-night revelry that runs past midnight into the next calendar day. The line is typically encountered as a standalone aphorism in quotation collections and holiday-themed miscellanies rather than as a passage traceable to a single identifiable speaker or publication, which is why it circulates under “Anonymous.”

The joke hinges on a playful inversion of timekeeping: the “morning” of March 17 is said to be made up of the night before, only lightly “flavored” by the actual morning that follows. Beneath the humor is a cultural observation about how communal festivals can blur ordinary boundaries—between night and day, restraint and indulgence, the sacred and the secular. The phrasing also gently satirizes the idea of national familiarity (“Anyone acquainted with Ireland knows…”) to present the claim as common knowledge, turning a stereotype about celebration into a compact, memorable epigram.