The Discovery of the Celendrical Date Line

Ferdinand Magellan

It was Antonio Pigafetta (c. 1491-c. 1535), the Italian chronicler of the first circumnavigation of the world by the Portuguese explorer and navigator Ferdinand Magellan (1480-1521), who first mentioned a peculiar incident that had occurred during the voyage: somewhere along the journey a whole day had apparently been ‘lost’.

When Pigafetta, one of the eighteen survivors of the original 270-odd crew members who had set out from the Spanish port of San Lúcar de Barrameda in September 1519, nearly three years later sighted the Cape Verde Islands, he noted:

“On Wednesday, the ninth of July [1522], we arrived at one these islands named Santiago, where we immediately sent the boat ashore to obtain provisions. [...] And we charged our men in the boat that, when they were ashore, they should ask what day it was. They were answered that to the Portuguese it was Thursday, at which they were much amazed, for to us it was Wednesday, and we knew not how we had fallen into error. For every day I, being always in health, had written down each day without any intermission. But, as we were told since, there had been no mistake, for we had always made our voyage westward and had returned to the same place of departure as the sun, wherefore the long voyage had brought the gain of twenty-four hours, as is clearly seen.”

The story of the ‘lost day’ experienced by Magellan’s crew was also transmitted in a different version by Pietro Martire d’Anghiera (1457-1526), who learned of their account at the court of Charles V in Valladolid, in the third decade of his De orbe novo decades (1530). This passage was translated by Richard Eden in The Decades of the Newe Worlde or West India (1555) as:

“And amonge other notable thynges by hym [Pietro Martire d’Anghiera] wrytten as touchynge that vyage, this is one, that the Spanyardes hauynge sayled abowt three yeares and one moneth, and the most of them notynge the dayes, day by day (as is the maner of all them that sayle by the Ocean) they founde when they were returned to Spayne, that they had loste one day. So that at theyr arryuall at the porte of Siuile [Seville] beinge the seventh day of September, was by theyr accompt but the sixth day. And where as Don Peter Martyr declared the strange effecte of this thynge to a certeyne excellente man [Gaspari Contarini of Venice] who for his singuler lernynge was greately aduaunced to honoure in his common welthe and made Themperours ambassadoure, this woorthy gentelman who was also a greate Philosopher and Astronomer, answered that it coulde not otherwyse chaunce unto them hauynge sayled three years continually, euer folowynge the soonne towards the West. And sayde furthermore that they of owlde tyme obserued that all suche as sayled behinde the soonne towarde the West, dyd greatly lenghten the day.”

Pietro Martire d’Anghiera’s lengthy discussions with the survivors of Magellan’s expedition and the Venetian astronomer and philosopher Gasparo Contarini (1483-1542) on this topic were summed up at the end of the fifth decade of his De orbe novo decades, addressed to Pope Adrian VI and translated by Michael Lok in De Nouo Orbe, or the Historie of the west Indies (1612) as:

“One thing remaineth which will fill ye Readers with great admiration, especially those, who thinke they haue ye wandering courses of the Heauens familiar before hande. When this ship [with the survivors of Magellan’s expedition] came backe to the Gorgodes [Cape Verde Islands], ye saylers thought it had bin Wedensday, but found it to be Thursday. Whereupō they say that in that wandring course, they lost one day, in that space of 3 yeeres. But I replyed to them your preists peraduenture deceiued you by omitting ye day either in their Celebrations, or in ye accoūt of howers. They answeared me againe what doe you think it possible that all, especially wise men, & wel experienced could fal into so foule an Error? It is a common case, to keep a ready account of ye dayes and monthes, because many had with thē bookes of the cōputatiō of howers, & knewe very well what was dayly to be accoūted. In the howers especially of the blessed Virgin, to whom we prostrated our selues euery momēt, desiring her protectiō in these, & in the commemoration of the deade, many spent ye vacant time.
Direct your thoughts therefore another way, without all questiō wee lost a day. These remēber this, others other things, & diuers diuers things, but all agree, that they had lost a day. I added moreouer: my friends, remember ye yeere following after your departure (which was 1520) was leape yeere, least peraduenture you were deceiued thereby. They affirmed, that they gaue Pigmean February 29 dayes that yeere, and forgot not the leape yeere at ye Kalendes of March. These 18 persons which remained, were altogether vnlearned, so they say all, one after another.
Being much disquieted and trobled with that care, I conferred with Gasper Contarinus (a man not meanely instructed in all kinde of literature) who then was Embassadour with the Emperour for his famous commonwealth of Venice. Whereby wee know (discussinge the matter with diuers arguments) that this strange report, neuer heard before, might very well be, after this manner: This Castelleā ship set sayle frō ye Ilāds of Gorgodes towards ye West, which way also the Sunne goeth. Thence it came to passe, that hauinge followed the Sunne, they had euery day longer, according to the quantity of the way they made, wherefore hauinge perfited the Circle, which the Sunne performeth in 24. howers towards the West, it cōsumed & spent one whole day, therefore it had fewer days by one, then they who for that space of time, kept one certaine place of aboade. But if the Portugall Fleete, which sayleth toward the East, should returne againe vnto the Gorgodes, continuing their course vnto the East, by this way and Nauigatio, now first foūd & discouered to mortall men, no man wold doubt seeing they shuld haue shorter dayes, hauing perfited ye Circle, but that 24. whole howres shuld remaine vnto thē ouer & aboue, and so one whole day, wherefore they should recken more by one. And so if either fleete, to witt, the Castellane and the Portugall, had set sayle the same day from the Gorgodes, and the Castellane had sayled towardes the West, and the Portugalles had towards the East, turninge sterne to sterne, and had returned to the Gorgodes, by these diuers wayes, in the same space of time, and at ye same moment, if that day had bin Thursday to the Gorgodes, it had bin Wedensday to the Castellanes, to whom a whole day was consumed into longer dayes. But to the Portugalles, to whom by shorteninge of the dayes, one day remained ouer & aboue the same day should be Friday. Let Philosophers more deeply discusse this matter, we yeeld these reasons for the present.”

The Testimony of Later Circumnavigators

Francis Drake (Buckland Abbey: oil on canvas by Marcus Gheeraerts)

Nearly sixty years later, the same phenomenon was observed by the crew members of the fleet of the English explorer Francis Drake (c. 1540-1596), when in September 1580 they arrived back again in Plymouth after a long westward voyage around the world that had started in late 1577.

“The 22 day [of September] we were in the height of the Canaries. And the 26 of Sept. (which was Monday in the iust and ordinary reckoning of those that had stayed at home in one place or countrie, but in our computation was the Lords day or Sonday) we safely with ioyfull minds and thankfull hearts to God, arrived at Plimoth, the place of our first setting forth, after we had spent 2 yeares 10 moneths and some few odde daies beside, in seeing the wonders of the Lord in the deep, in discouering so many admirable things, in going through with so many strange aduentures, in escaping out of so many dangers, and ouercomming so many difficulties in this our encompassing of this neather globe, and passing round about the world, which we haue related.”

In January 1594, the Florentine merchant Francesco Carletti (c. 1573-1636) set out on a remarkable circumnavigation of the world in westward direction that lasted until the year 1606 and which he described in his Ragionamenti del mio viaggio intorno al mondo. Travelling without great haste via the Spanish dominions, crossing the isthmus of Panama and stopping over at Manila, he booked a passage for the Japanese port of Nagasaki in 1597. Upon his arrival there, he observed:

“And we found a difference in reckoning the days between us, who had come from the city of Manila, and the Portuguese who had come from that of Macao, an island of China. These Portuguese, having left Lisbon and navigated constantly eastward, had reached Japan as the farthest point of their journeying. During their voyage, the sun having risen for them constantly earlier, they had gained twelve hours of a natural day. We, on the contrary, having left the port of Sanlu’car de Barrameda in Spain and navigated steadily westward and having lost daylight constantly because the sun kept rising later, had lost twelve hours. So when we discussed it with them, we found that we had reached a difference of one day. And when they said that it was Sunday, we counted up to Saturday. Had I pursued my voyage around the entire world without having met those Portuguese, by the time of my arrival in Europe, whence I first had departed, I should have lost exactly a whole day of twenty-four hours.
For I, having moved constantly from the east toward the west, changing meridians and therefore making the day later for myself, would have encountered this difference of one day as caused, as I have said, by the later or earlier rising and setting of the sun in the diverse meridians, which continue changing daily for those who navigate toward the east and toward the west. And it is true that in the Philippine Islands on that same day when the Spaniards and their Church are celebrating Holy Saturday, those who are in Japan–that is, the Portuguese and their Church–are eating meat, because for them it is the Day of the Resurrection. So that if they were moving swiftly enough to reach Manila the next day, as is said to have happened to some navigators, they would celebrate the same Easter or other solemnity twice. And if they were to arrive on the day when those people celebrate the feast, it would befall them to return on Holy Saturday. On the other hand, if those from Manila should set out on the day when they solemnize Christmas and reach the island of Macao, where the Portuguese are, they would find those others at the second feast of Saint Stephen, and would thus celebrate one and another solemnity on the same day. And if they were able to arrive on the day before Christmas by their count, they would be able to eat meat without having fasted on the preceding day.
And this suffices for knowledge of that occurrence, perhaps not better understood earlier because the world had not been circumnavigated in olden times as it now is traveled around by value and virtue of the two crowns of Castile and Portugal, who have showed the way, the former navigating toward the east and reaching China and Japan, the other toward the west and reaching these Philippine Islands, about one thousand miles from the island of Macao in China, the residence of the Portuguese. Together, those two crowns have come to make a circle around the whole world, a thing that certainly is worthy of being much exalted and praised in those two nations, with the languages of which, and by means of whose navigations, anyone can enter into that magnificent enterprise and in less than four years go around the entire universe both by way of the East Indies and by way of the West [...].”

Dutch navigators also had similar experiences. When Jacob le Maire (c. 1585-1616), after an arduous voyage around the southern tip of South America (named Cape Horn after the Dutch town of Hoorn, le Maire’s port of departure), finally reached the port of Batavia on Java in October 1616, he noted in his journal:

“This [the confiscation of his ship and cargo by the authorities of the Dutch East India Company] was done vpon Munday the first of Nouember, after our reckoning, but vpon a Tewsday the second of Nouember, by our countrimens reckoning there. The reason of the difference of the time fell out thus, as we sayled westward from our owne countrie, and had with the sunne compassed the Globe of the world, we hadde one night, or sun-setting lesse then they, and they that come out of the west and sayle to the east, thereby had one day or sun-setting more then we, which make a quarter difference, and so as we made our reckoning of the time then with our selues, and did the like with our countrimen, that weeke we lost the Tewsdaie, leaping from Munday to Wednesdaie, and so hadde one weeke of 6 dayes.”

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