National Corn Dog day fell on 17 March 2018, related to a US patent which issued March 26, 1929

Wikipedia notes:


National Corndog Day is a celebration concerning basketball, the corn dog (A corn dog is usually a hot dog sausage coated in a thick layer of cornmeal batter), Tater Tots, and American beer that occurs in March of every year on the first Saturday of the NCAA Men's Division I Basketball Championship.




As to patents, note Combined dipping, cooking, and article-holding apparatus , US 1706491, to Stanley S. Jenkins in 1929 which included:



I have discovered that articles of food such, for instance, as wieners, boiled ham, hard boiled eggs, cheese, sliced peaches, pineapples, bananas and like fruit, and cherries, dates, figs, strawberries, etc., when impaled on sticks and dipped in a batter, which includes in its ingredients a self rising flour, and then deep fried in a vegetable oil at a temperature of about 390 F., the resultant food product ona stick fora handle is a clean, wholesome and tasty refreshment; and to provide a simple, inexpensively constructed and sanitary apparatus for cooking such food products in quantities is a further object of the invention.