Answer: Independence Day

If you’ve paid any attention to the U.S. calendar of official and unofficial holidays, then you’ve certainly noticed that some holidays are fixed (Christmas Day is always December 25th, for example) while other holidays are flexible as to which specific date they fall on. Memorial Day, for example, always falls on the last Monday in May and Labor Day always falls on the first Monday in September. In fact, it’s no coincidence that Washington’s Birthday (also called President’s Day by some) and Columbus Day fall on Mondays too.

Those magic three day weekend holidays were fixed in time by the 1968 Uniform Monday Holiday Act, a fine piece of legislation introduced by U.S. Representative Robert McClory, a Republican from Illinois, that went into effect on January 1, 1971. The goal was to align federal holidays with weekends so that federal workers (and the workers at numerous private businesses that observed the holidays) could enjoy more productive vacation time instead of getting oddball days off in the middle of the week here and there.

In addition to the aforementioned holidays, the original legislation he wrote up also included setting Independence Day to fall on the first Monday of July. This, he argued, was a reasonable move since we don’t technically know when the Declaration of Independence was written and, by various historical accounts, independence could have been declared anywhere in early July (but was likely July 2nd). By the 1960s, however, the idea of the day being “The Fourth of July” and no other day was too firmly enshrined in the nation’s consciousness though. While everyone agreed all those other three day weekends sounded mighty fine, there was strong opposition to letting Independence Day drift about at the start of the month.

For the curious, the next time the 4th of July will fall on a Monday is 2022.