The southern Philippines, in an 1852 map (Image: Geographicus Rare Antique Maps/Wikimedia)

One of the marvels of modern civilization is that, for the most part, humans all around the globe have agreed on one system for counting days and hours. This is a recent development. While people have generally relied on the cycles of the moon, Earth and sun to measure time, at least 80 different calendars have been used, some more closely aligned than others.

And no system is perfect. The most common timekeeper, the Gregorian calendar, is filled with eccentricities. February is so short, random months have 30 days, and the formula for leap-years defies logic (it is a lot more complicated than “every four years”). This all has to do with keeping Easter in the right place; there’s no good reason, on the other hand, for the seven day week. But, however messy the system, it’s our system, and most of Earth has agreed to stick with it.

Given all that, you don’t just skip a day.

But in 1844, that’s exactly what the Philippines did. The governor-general at the time, the well-named Narciso Claveria, declared that January 1, 1845 would come directly after December 30, 1844. December 31, 1844, would not happen in the Philippines.

The governor-general had his reasons for this decision. Because of the islands’ colonial history, the Philippines used the date to the east, the American date. To the west of the Philippines, though, in Asia, the date was one tick ahead. This difference is the result of a mind-bending principle of navigation, in which ships gain ground on or lose time, depending on what direction they go. The practical result of the Philippines adopting the date of ships coming from the east, as Avraham Ariel and Nora Ariel Berger explain in Plotting the Globe, was that it was a different date than its geographical peers, oriented to the west. “Sunday in Manila was Monday in Batavia (now Jakarta), just 1700 miles due south,” they write.

How the calendar date worked pre-1845 (Image: L’astronomie/Public domain)

By 1844, the colonial trading patterns that had put the Philippines on the American date had shifted–its trade was now coming from the west–and it made sense to switch to the Asian date. To catch up, the Philippines had to skip a day. This was well before the International Date Line was officially established, and some cartographers had no idea the islands had made the switch. For decades, they put the Philippines on the wrong date.

Countries have shifted over the International Date Line only a few times since the it was established in 1884. In 1993, one atoll of the Marshall Islands flipped to the Asian side of the date line, skipping a Saturday in August. And, most recently, in 2011, Samoa and Tokelau made the same switch.

Samoa had actually switched once before. In 1892, American trading partners convinced the king to flip to their side of the date line, and the country lived through July 4, 1892 twice. But 119 years later, the economic geography of the island had changed, and most business was being done with Australia and New Zealand. To make the jump back to the Asian date Samoa and Tokelau skipped Dec. 30, 2011.

This time, unlike with the poor Philippines, the rest of the world went along with their choice: if you’re reading this in America, it’s already tomorrow in Samoa. 

Welcome to No One’s Watching Week, the time of the year when the readers are away and your tireless editors have run amok. For this week only, Atlas ObscuraNew RepublicPopular MechanicsPacific StandardThe Paris Review, and Mental Floss will be swapping content that is too ​out there​ for any other week in 2015.