Have NASA Computers Proved Joshua’s Long Day?

The Claim

From time to time, one hears that NASA computers have proved the account of the unusual day that accompanied the Battle of Gibeon found in Joshua 10:12–14. This marvelous little story about NASA computers began circulating in the late 1960s and early 1970s, during the heyday of the Apollo program. According to the story, in preparation for the Apollo moon landings, a computer at NASA calculated the positions of the earth, moon, and other solar system bodies with great precision far into the past and future.

This computer program produced a glitch in the fifteenth century BC, a glitch caused by solar system bodies not being in their correct positions, indicating that nearly a day was missing from time. An additional 40 minutes also was missing several centuries later, so that the total missing time was one full day.

Supposedly, NASA scientists and engineers puzzled over this problem until one of them opened the Bible to Joshua 10:12–14 and 2 Kings 20:8–11. The NASA personnel supposedly came to realize that their missing day could be explained by addition of nearly a day at the time of Joshua and an additional 40 minutes at the time of Hezekiah, thus proving that these biblical events actually occurred.

This story was carried in a few newspapers at the time, but it enjoyed widespread circulation among Christian audiences in the United States. It is less common in the United States now, but apparently this story has begun to circulate in other parts of the world. Nearly a half century ago, computers were a bit mysterious, and many people thought that computers could do almost anything. People think that quite a bit less now, but the story continues to circulate, primarily because it has been around for so long and has appeared in so many sources that it is easy to find references for the story.

The Problem

The person who appears to be responsible for this story is Harold Hill, president of the Curtis Engine Company in the late 1960s. Hill told the story a number of times before finally committing it to print in a 1974 book, How to Live Like a King’s Kid. Hill’s company had done contract work for NASA during the Apollo program, and Hill claimed that during this time he became aware of the computer confirmation of Joshua’s long day through his work at NASA. In some versions of the story, Hill worked for NASA, but Hill never did. Furthermore, the sort of work that Hill’s company did would not have placed him in a position to be privy to this sort of information. Hill claimed to have seen documentation of this supposed event as a NASA memo, but Hill could not produce the memo. Some people have speculated that if Hill actually did see such a memo, the memo may have been an April Fool’s Day prank.

The problem with this story is that a computer could not find such a discrepancy in the positions of solar system bodies.

The problem with this story is that a computer could not find such a discrepancy in the positions of solar system bodies. In order for a discrepancy to be found, we must know exactly where things were at some time in the past prior to Joshua’s long day, so that the calculated positions can be compared. A computer can calculate only where things ought to have been in the past; it cannot compute where things actually were in order to make a comparison. Computers can be used to determine how much the earth’s rotation has slowed over the centuries due to the tidal interaction between the earth and moon. We can calculate into the past when and where total solar eclipses should have occurred on the earth absent the earth’s slowing rotation. From historical records we know when and where certain eclipses were actually observed. From this discrepancy, we can measure how much the earth’s rotation has slowed. However, in the case of Hill’s computer story, such a comparison is not possible, because we do not have information as to the location of various solar system bodies at an earlier time.

The Truth

This story is not new, but rather it is a modern retelling of an even older story. In the 1930s, Harry Rimmer made reference to how science had proved the missing day of Joshua, and this story continued to circulate within Christian circles for decades. Rimmer’s mention of this may have been the origin of Hill’s story. Rimmer based his statement upon an 1890 book by C. A. L. Totten, Joshua’s Long Day and the Dial of Ahaz, a Scientific Vindication and “a Midnight Cry.” Totten did a very elaborate computation of the date of the battle of Gibeon since the creation.

He reasoned that the battle was on the twenty-fourth day of the fourth month of the Hebrew civil calendar in the 2,555th year after the creation. This was the 933,285th day since creation. From this, Totten determined that this day was a Tuesday. Next, Totten calculated backward in time from June 17, 1890 to the battle of Gibeon. He concluded that the battle was 1,217,530 days previously, which was a Wednesday. Hence, there was a day missing. Of course, Totten’s computation required very precise dates, something that most people today would find ludicrous. However, Totten managed to obtain some audience in the late 19th century. While most people today are not impressed with such an approach, apparently invoking a computer, as in the Hill story, is sufficient to convince some people today. This story has been debunked many times, so it is a shame that it keeps being repeated.

The fact that NASA computers have not proved the account of Joshua’s long day does not mean that there was no miracle at the battle of Gibeon as recorded in the book of Joshua. We know that God’s word is inspired. Therefore, we know that the Bible is authoritative in all things, including history. Since Joshua 10:12–14 tells us that God performed this miracle, we can be assured that indeed He did perform this miracle. As Joshua 10:14 described it, “There has been no day like it before or since” (ESV).