It’s April 1, 1891. Twenty-nine-year-old William Wrigley Jr. founds his namesake company in Chicago. Was the April Fool’s Day date a coincidence, or an indication of Wrigley’s sense of humor?

Perhaps there’s another reason why Wrigley and so many other American companies, including Apple, share an April 1 founding date.

An answer may be found in the role that the British accounting system played in a young America’s financial system. The United Kingdom and most of its former colonies are on an April-to-April fiscal year. One bit of folklore speculates that the April-to-April calendar was designed to avoid bottlenecks during the holiday season and save unfortunate accountants from having to pore over the books on New Year’s Eve.

An even more arcane explanation may lie in the fact that, in the ancient Julian calendar, the end of the year was 25 March, which corresponds to April 5 on our modern Gregorian calendar. It’s possible that the April “new year” was a time set aside for producing accounts and end-of-year reconciliations.

In any case, with thousands of British chartered accounts immigrating to the United States between 1875 and 1914, it would not have been unusual for them to recommend April 1 as an official founding or incorporation date to their American clients.

So the next time you think that a company’s founder had a great sense of humor by launching their enterprise on April Fool’s Day, you might think twice. In looking for a possible explanation, go no further than the wisdom of political strategist James Carville, who reminded us: It’s the economy, stupid.