On what date did the 20th century technically begin?

Which spicy Cajun smoked sausage is often found in gumbo? What kind of cake is traditionally cut together by a couple who have just tied the knot? Which calculating device do the Chinese call the suanpan? Calcutta was once the capital of British India; which newly built city became the capital in 1931? In 1963, a long dispute between California and Arizona over water rights to which river was settled by the Supreme Cour… Which "pet" did California advertising man Gary Dahl create in 1975? The California Institute of Technology is located in which city? Which thistle-like vegetable, grown mainly in California, has an edible heart?