grudzień

Grudzień is December, a name linked to gruda, a clod or lump, and in literary use frozen ground. In dates it takes the genitive form grudnia: dnia dwudziestego grudnia, on the twentieth of December. The -zie- drops out, so grudnia is shorter than grudzień.

Entries from late December can be dated Julian and Gregorian at once, and the twelve-day gap can push the second date into January of the next year. The Roman numeral for December is XII.