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The Pitcairn Island Calendar Mystery

by Brian Dunning, Nov 10 2011

Pitcairn Island (Photo: NOAA)

The year was 1808, and men of the American trading ship Topaz landed on Pitcairn Island, thus becoming the first to contact the colony founded by the infamous mutineers of the Bounty.

They found a tiny but prosperous village consisting of one remaining mutineer, a number of Tahitian women, and dozens of children. Life was well ordered; homes were clean and well built, the sabbath was observed, the log was meticulously maintained, and the calendar was wrong.

By one day.

It took a bit of figuring, but this minor mystery was eventually solved. When the Bounty mutineers had sailed east from Tahiti in search of Pitcairn Island, they had crossed the international date line. Perhaps it was because the ship’s complement of educated men had been sharply reduced, perhaps it was the stress of having other things to worry about; but for one reason or another, Fletcher Christian had never caught the error. The calendar was maintained for a quarter of a century on Pitcairn Island before the Topaz arrived and found the surviving Englishman, John Adams, still keeping a strict clock.

Savvy readers might catch a possible error in this reasoning: Tahiti lies east of the international date line. Pitcairn Island is on the same day as Tahiti; no crossing of the date line should have taken place. But this, too, has an explanation. Before the middle of the nineteenth century, most of the islands of the South Pacific were west of the date line. Only then did American influence gain enough traction to convince much of the region to sync up with the United States (Tahiti included), giving the date line the twisted, zig-zagging pattern it has now.

But this is not all just ancient history. This year, Samoa will skip over December 30 and move back to the west side of the date line, bringing it into sync with its major trading partners Australia, New Zealand, and Asia.

The Pitcairn Islanders finally did correct their calendar after the error was confirmed by later ships from England. Of course, it was probably easier then than it would have been to follow Samoa’s example today.

20 Responses to “The Pitcairn Island Calendar Mystery”

  1. MaikU says:

    Yet still… Aliens.

  2. Grant says:

    Samoa also recently switched from left hand drive to right, again to better match NZ and Australia.

    Changing your entire country overnight to drive on the other side of the road would no doubt have been more difficult than a date change.

    • tmac57 says:

      I take it that you are talking about the car,and not the side of the road? That is, they will be driving on the left hand side of the road,correct?

      • Jeff says:

        I was in Samoa in 2009 when the switch happened. They did switch the side of the road cars drove on. They went from driving on the right (as in the USA) to driving on the left (as in New Zealand). The reasoning was that the majority of the cars they import come from New Zealand, so it made more sense to use right-hand-drive cars (which use the left side of the road).

        The changeover was surprisingly smooth and safe. It was well publicized in advance, and the locals drive ridiculously slow anyway. At midnight before the switch, teams of workers throughout the island repainted arrows in the road and changed the signage. There are only a few stoplights in the entire country, so they were relatively easy to change too. Of course, some village elders protested the change, but there isn’t much they could do. I went back to Samoa last summer, and you’d never know it was anything different.

    • SocraticGadfly says:

      IIRC, Sweden did the swap not too many years ago, going to American-style driving. Beyond normal highways, “flipping” exit/entrance ramps on freeways is a biggie.

  3. Bill says:

    Changing your entire country overnight to drive on the other side of the road would no doubt have been more difficult than a date change.

    Nah…changing the country to drive on the other side of the road is easy. It’s the individual drivers that you gotta worry about.

    • Markx says:

      Ha ha – I think it would depend entirely on the driving culture.

      In many South East Asian countries where traffic tends to take the ‘fish in water’ approach people delay with obstructions and the unexpected in a very calm and benign way. A car driving the wrong way is simply avoided, perhaps with a toot on the horn, but no-one becomes aghast or has conniptions. Once when a single two lane road here was converted to a dual carriage way (a parallel road was built) no one bothered to erect any detour or direction signs, and for a while, both roads operated as two way. Eventually, each of the carriage ways drifted towards having only one direction, although for a month or two we had to watch out for the odd stray taxi coming the wrong way.

      In some countries (Australia, my beloved home, for instance) drivers regard their road rights as absolute laws carved in stone. They will scream and foam at the mouth at the slightest impingement of their lane, or their right of way. Many seem willing to fight and die on the spot for these rights. They will foam and spit out every Anglo-Saxon crudity they know, and threaten to hunt down and kill every existing member of your known family if you pull into their lane and actually cause them to have to lift a foot from the accelerator for a second. I think they would have difficulty with change.

      Mind you, I think the road toll is a hell of lot lower in Oz, but perhaps this gets balanced out by high blood pressure strokes.

  4. Dennis L. says:

    Perhaps as a consequence of this error in computing an accurate local time Fletcher Christian, the leader of the Bounty mutineers, names his first born son, Thursday October Christian, after his purported birth day. However, it turned out that Thursday October was actually born on a Friday.

    • True, in fact one of the British naval reports that I read referred to the young man as Friday October Christian. That would have been a nice addition to this post. Thanks.

  5. Trimegistus says:

    I heard a joke from Sweden about the switchover: cars made the change on January 1, trucks a week later.

  6. Did the International Date Line exist in the early 19th century? Of course not. Nobody had such a concept at that time. In fact, when Jules Verne wrote his “Around the World in 80 Days” in 1873, a plot device is that the travelers thought they had been out 81 days and missed their deadline, but it was actually just 80, because they had gained a day. Whenever you travel east 15 degrees, you gain an hour. By traveling 360 degrees east, Verne’s travelers had gained 24 hours, which they would have corrected by subtracting a day when they crossed the dateline, if such a thing had existed at that time. They had actually experienced 81 sunrises and sunsets, one of which was caused by their own circumnavigation of the globe. This plot device would not have worked unless people were unfamiliar with the problem, i.e. no dateline had yet been officially established. Wikipedia says “The nautical date line is a de jure construction determined by international agreement. It is the result of the 1917 Anglo-French Conference on Time-keeping at Sea” (article on International Date Line). Before that, different regions matched their “day” to whatever country was their most significant trading partner.

    The Americans who reached Pitcarin Island had presumably sailed west, losing hours. The English mutineers who reached it had presumably sailed east, gaining hours. No wonder they had a disagreement about the day.

  7. gdave says:

    @Robert Scheaffer:

    You’re both right and wrong.

    You are indeed right about why the American sailors and the Pitcairn Islanders disagreed about the date. And you are right that there was de jure IDL prior to 1917 – indeed there still isn’t really one now. No one other than the UK and France is bound by the 1917 Anglo-French Conference on Time-keeping at Sea, but just about everybody abides by it as a matter of convenience.

    However, the concept of a date line certainly did exist in the 19th century. Look a little further down in the Wikipedia article you cite and you’ll see that the Philippines switched from one side of the date line to the other on Dec 30 1844/Jan 1 1845 (skipping Dec 31 1844). And the concept goes back centuries before that. According to the website of the Institute for History and Foundations of Mathematics and the Physical Sciences, the concept was mentioned by Rabbi Yehuda ben Shemuel Ha-Levi around 1140.

    By the 19th century, the “navigator’s paradox” was definitely common knowledge among British sailors and navigators, although perhaps not many readers of Jules Verne. Fletcher Christian would certainly have known to compensate for crossing the 180 degree meridian (as calculated from the Greenwich Meridian).

    On the other other hand, not compensating for it isn’t really an “error.” It wouldn’t have really served any useful purpose to compensate for crossing the de facto date line, given that the Pitcairn settlement was remote and out of contact with the rest of the world for 25 years.

  8. gdave says:


    What I should have written in my second to last paragraph above was that by the late 18th century, the “navigator’s paradox” was common knowledge among British sailors, and Fletcher Christian would almost certainly have been aware of it, even if many readers of Jules Verne a century later weren’t.

    Also, I have trouble wrapping my head around the whole date line/gain a day/lose a day business, so I’m quite possibly wrong about whether Fletcher Christian “should” have compensated for crossing a de facto date line, but I think I’m on pretty solid ground in saying that he would at least have been aware of the concept, as would the crew of the Topaz.

  9. Adam C says:

    Am I the only one who caught the error at the end of the last paragraph or just the only one who will say anything about it?
    “Of course, it was probably easier then than it would have been to follow Samoa’s example today.”

  10. Steve says:


    Do you have any documentation that says the men of the Topaz asked the survivors about the date? As this article that you linked in your Skeptoid story about Fletcher Christian refers to the incorrect date and the sole survivor blames it on the crew of the Topaz giving them the wrong date, not then having the wrong date already as would have happened if they did or didn’t compensate for the IDL.

    Here’s the quote from Capt Pipon: “On our arrival here we found that John Adams was mistaken in the day of the week & Month: he considered it to be Sunday the 18 Sep’r 1811 [1814] & to his credit they were keeping the Sabbath very properly making it a day of rest & prayer: whereas it was Saturday the 17th, by his account he had been misled by the American Captain of the Topaz when she touched here”.

    Would the incorrect charted position of the island have anything to do with it. Pipon’s log seems to think that Pitcairn wasn’t where the charts showed it to be. If the American sailors thought they were further East than they were that might account for the inaccuracy.

  11. Joseph Cottrell says:

    I guess we should take it as a complement that left-hand drive/right lane driving is referred to as “American style,” but the reality is that (I am fairly sure) Great Britain, Australia and New Zealand are the only places left on the planet (with the addition of maybe a few tiny little countries such as the Seychelles) where left lane driving is the norm. Which makes it truly bizarre when you drive on to a ferry or the Chunnel train in England and off in France. . .

    • Markx says:

      Left side lane driving?

      Japan, Thailand, Malaysia, Singapore, Australia, New Zealand, Indonesia, India, England, that I know of!