The Day Line by Joseph Harvey Waggoner

Pacific Seventh-day Adventist Publishing Association · Oakland, California · May 3, 1877

The Day Line.

By Joseph Harvey Waggoner

It is singular how this subject, plain in itself, is mystified by some people. The following extract is from one of the leading Catholic papers in the United States in answer to a request for information in regard to the day line:—

“Geographers have not established a universal day line. There is a day line between each two towns or places on opposite sides of the globe, but this line is always changing, and were geographers to define all the day lines, the largest map could not contain them, for the horizon of a place is its day line. When it is noon at Washington, it is 9 o’clock in the morning at San Francisco, 11 o’clock at Jefferson City, Mo.; 5 minutes to 11 at St. Paul, Minn., and 20 minutes to 10 at Salt Lake City. You can therefore see that night does not come at the same time to all these places, and consequently, that a universal day line is impossible.”

The paper is ably conducted—most Catholic papers are—as far as general and religious intelligence are concerned, yet it would be hard to find a paragraph betraying such utter ignorance of a well-known fact. Had the question been, at what point the sun shines all round the world at once, the above would have been a satisfactory answer. And that is as far as the editor seems to have understood the subject.

It is indeed true that geographers have not established a universal day line, for they have no need of it; it does not fall within the range of ordinary geography. But navigators have established such a line and to them it is indispensable. We cannot present the question of fact more clearly than we presented it in the Review of Baird on the Sabbath:—

“It is well known that in traveling either east or west we find our time-pieces continually varying from the time of the different localities through which we pass. To keep our watches with sun time, that is, true, or correct time, we must often set them by local time. The whole amount of such changes in traveling around the world, will be 24 hours. For if we travel eastward we must correct our time-pieces by setting them forward four minutes to each degree, one hour for every fifteen degrees, and of course twenty-four hours for the complete circle. Having changed our time twenty-four hours in going round the world, it is evident that, on returning to the locality whence we started, we find there the same time with which we started, and to conform to that time we must drop out of our count all the variations we have made in traveling. The effect is the same in traveling westward, but the order is reversed.

“It is always a fact that a person starting in China and traveling westward will find that his enumeration of the days of the week will agree with that of every place through which he passes until he again reaches the Pacific, in California. And reversing the order, starting at San Francisco, he may travel eastward, and he will find that his days of the week agree with those of every place through which he passes, until he reaches the other shore of the Pacific. Through Asia, through Europe, across the Atlantic, and through America, no change is found. But let him start from the coast of China and cross the Pacific Ocean and the case is different. On landing at San Francisco he will find his week one day in advance of those living there, unless he corrected his count by one day, on the ocean. And in like manner, if he crosses from California to China, he will find himself one day behind the inhabitants of China unless he corrected his time, by one whole day, on the passage.”

For convenience, navigators have chosen the even 180th degree from Greenwich. This is not the true day line, because it cannot be universal. It passes through a part of Asia and through a small island in the Pacific, and it would create confusion if it were adopted in those places. Perhaps some readers would better appreciate this if we say something more on the necessity of a day line, or of the correction of our time in traveling.

The quotation above says, “When it is noon at Washington it is nine o’clock in the morning at San Francisco.” Then Washington is three hours farther advanced in the same day than San Francisco, and of course Washington will see the next day three hours before it is seen in San Francisco. And he who starts from San Francisco with a watch indicating true time will find that his watch is three hours behind true time when he arrives in Washington. Say I am now writing in San Francisco at noon Monday, April 23. Going instantly to Washington, we find at the same time it is Monday, 3 P. M. The same distance east of Washington we find 6 P. M., and once more the same distance we find 9 P. M. Counting the day from sunset, and it is evident that at some point in the last named distance we suddenly passed from Monday into Tuesday, though it is still Monday where we started. Now if we should insist, inasmuch as we started with true time, and our watches are accurate time-keepers, that therefore they indicated true time at all the places we visit we should find ourselves disagreeing in time with all the people of the several places and with the sun also, the great time indicator.

We are thus explicit on this point to fix on the mind of the reader the fact that we must correct our time in traveling. Having, as supposed, changed our watches nine full hours, it is plain to see that if we return to San Francisco they will vary nine hours from true time here. Hence, we must drop nine hours to restore our reckoning.

We have now seen the necessity of changing our time, but we have not yet found the day line. In traveling eastward we have changed our time to keep us in harmony with the inhabitants of the several places visited, and in this we have succeeded. Continuing our journey we pass to the opposite side of the earth, and our time varies twelve hours from San Francisco time. True, our watches in both places indicate twelve o’clock, but not the same twelve o’clock; one is noon, the other is midnight. Continuing to travel in the same direction the same distance, we will change our time to the same amount, namely, twelve hours more, making twenty-four hours. But this will bring us to our starting place, and again it is twelve, noon, both to us and to the people of the city, but not the same noon according to our reckoning. We have been regularly setting our time pieces forward, and in the whole journey have set them forward twenty-four hours. But if it is Monday noon to the people of San Francisco, and our reckoning is twenty-four hours ahead of theirs, it is, of course, Tuesday noon to us at the same time. Now if we drop twenty-four hours out of our reckoning, one day, we shall restore ourselves to San Francisco time.

Now we come to the interesting point. In our travels we were constantly changing our time-pieces to avoid any discrepancy of time between us and the inhabitants of the different places visited, and we succeeded all the way till we returned to the starting point, and here we found that by the same process, we had run into a discrepancy of twenty-four hours. This is a fact which we cannot ignore. Our earth is a globe—we travel round a circle. Were it an unlimited plane all corrections of time would be in the same direction, travel as far as we would. But as we compass the circle we find the necessity for a general correction of all the gradual changes we have made. This is made by what is called the day line. Such a line exists, as we have shown, in the Pacific Ocean. The line in the Pacific is recognized by all navigators, and is the only place where one can be located to prevent confusion and secure a uniform enumeration of the days of the week.

Two things are necessary in establishing a day line, which we will notice.

First, it must not strike through any habitable land. The 180th degree from Greenwich passes through the north-east part of Asia, and through an island in the Pacific. The only reason why no confusion is found in these points is that the line is not recognized in these points. The line is actually in the waters between Asia and America. Residents on the land need not regard this arbitrary line, and do not. An arbitrary line as the 180th degree, not far from the true line, answers every practical purpose of navigators. If recognized on the land there would be constant confusion, as it would be one day on one side of the line and another on the other side.

Secondly, it must be uniform. If it be in the middle of the ocean it must yet be uniform, or there would be discrepancy of dates. Thus, if a ship going westward should make the change at 170° west from Greenwich, and one going eastward at 190°, and they should meet between those parallels, their dates would not agree. The one going west would, after the change, have the time of Asia, while the one going east, would have changed to the time of America; therefore they could not agree. They would report having met each other on different days! Therefore the line of correction must be known and accepted by all who navigate the Pacific.

The question has been raised, If the tide of emigration had been eastward from Asia, instead of westward, would not the line have been in a different place? Perhaps so; but if it had been in the Atlantic it must unavoidably have passed through large bodies of land. The question is practically settled by this important fact, the tide of emigration was not eastward! We have the proper succession of days established by the word of God, and his providence secures the proper observance of that succession in all lands. We might ask, how would we mark the beginning of the day if the sun did not rise and set? But we should find very little profit in the discussion of the question. The providence and word of God are in harmony; we can no more change one than the other. Let us accept them as they are, and we shall be safe. J. H. WAGGONER.

San Francisco, April 23.