An eleven day festival beginning September 3rd and ending September 13th each year in honor of "The Greatest Holiday That Never Was". Bobunk refers to the erasure of an imaginary holiday mentioned by Salem the cat in Sabrina The Teenage Witch, whereby the holiday was literally erased from all time and memory.
Festivities for this holiday normally included copious amounts of alcohol, honoring of cats, food, and general merriment. While the third Saturday of November is often stated as the holiday Bobunk, history shows that the year 1752 and the month of September shows actual evidence of 11 days missing (attributed to the Julian to Gregorian calendar switch), and would be more appropriate for "The Greatest Holiday That Never Was" and the story about a holiday that was literally wiped from existence and memory.
With the Festival of Bobunk approaching, cats the world over began to stock their liquor cabinets in preparation, as well as aspirin and alkaseltzer for the expected hangovers lasting until New Years Eve.