Today the United States and Canada celebrate Labor Day (or Labour Day), while for the rest of you it's more likely just an ordinary September 1. Labor Day was established as US federal holiday in 1894 to honor the achievements of the American worker. But for all those living by the academic calendar, it’s the last gasp of summer, a reward for having survived the first week or two of classes after a long vacation.
September1 is a lowest-probability typo on the Ballard list, although it’s apparently an easy enough mistake for the fingers to make. There is 1 instance of it in the OhioLINK database, and 38 in WorldCat. If you have the day off, please restrain yourself from running to your own catalog to check!
(Miners with their children at the Labor Day celebration, Silverton, Colorado, September 1940 as photographed by Russell Lee, from the Library of Congress)