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An Historical Calendar Program

Have you ever wondered on what day of the week April 1 fell in the year 33? Or how about the day of the first full moon after the first day of spring that year? Or what age (number of days after new moon) was the moon on the twenty-fifth of December 2 B.C., the traditional date when the wise men visited the child Jesus? And what of October 19, 4001 B.C., the date we've elsewhere1 identified as the most likely date for the first day of creation?

Technical jargon

Well, if you have a DOS-based computer then do we have a program for you. Unfortunately, we cannot afford to send out another diskette mailing, at least, not just yet. At the time we did the carbon-14 program, we thought that it would be a one-shot deal. In the meantime, however, we have received several excellent ideas for programs. Insofar as these programs advance the cause of geocentricity and bible-based astronomy, it behooves us to make them as available as possible. For those reasons, members who request a program diskette will be sent one free of charge. Non-members may purchase them for $6.00 postpaid. Please specify disk size, and again, we can only support the “IBM” PC line. Sorry, because of the length of the source code, which runs six pages of fine print, we can not print the source code in the pages of the Biblical Astronomer. The source code (in QuickBASIC) is on the distribution diskette.

The creation week

Having done with all that technical jargon, what of our introductory questions? One of the most likely dates for the creation is October 19, 4001 B.C. That day was on a Sunday, which is the first day of the week. Although the moon was not created until the fourth day, October 19 marked the beginning of the month, namely, the date of new moon. In that year autumn started at the end of the fourth day of the week (Wednesday). That was the day when the sun, moon, and stars were created.2 So we see that on the week of October 19, 4001 B.C., the end of the creation of the sun and moon heralded the first day of autumn, and the moon was “new” (if the sun and moon had existed then) on the first day of creation. One may ask “Why didn't the new moon fall on the day the moon was created?” The reason is simple, the moon is a type of the church and the salvation of the church was planned from the foundation of the earth. Hence, theologically, the ecclesiastical moon had to be at its new phase at the start of the creation.

The date of the crucifixion

In the year of the crucifixion, A.D. 33, April 1 was on a Wednesday. The moon was 13 days old (full moon is 14 days) which means that April first was technically the fourteenth day of the lunar month. Now Jewish tradition has it that the moon had to be visible for the month to start. That is, some priest had to see the crescent moon to start the new month. That delays the start of the month by about 19 hours or so, so that the ecclesiastical fourteenth day would have been Thursday, April 2. This explains why Jesus both ate the passover with his disciples (Luke 22:15) and was himself the passover lamb. A.D. 33 was one of those circumstances where the actual new moon and ecclesiastical new moons were at variance, where it was “too close to call,” so that the purists could eat a passover on the “correct” day while the actual slaying of the lamb and the formal passover would take place the next day. So, Jesus observed a passover with his disciples in the upper room on the moon's ac tual 14th day, only to be sacrificed as the ecclesiastical passover lamb on the 14th day since the moon was observed by the priests at Jerusalem. Interestingly, the new moon and the first day of spring coincided that year. Presently the Jewish calendar does not allow the passover to fall on a Thursday, but the earliest traces of the current tradition which I have been able to find, date well after the fall of Jerusalem in the year 70. Is the April fool tradition related to this, the date when Judas betrayed his master, thinking to fool him?

The visit of the wise men

The traditional date for the visit of the wise men to the Christ child is December 25. The most likely year, both historically and astronomically, appears to be 2 B.C. Running the program we discover that in that year, December 25 fell on Thursday. It was the night of the new moon. Joseph, being warned to flee to Egypt after the wise men left, departed immediately. On the night of January 9-10 there was an eclipse of the moon (note latitude = 0° on the computer's lunar results). This eclipse is mentioned by Josephus as the one preceding Herod's death. Herod died about January 20. By the second of February he was dead and buried, his heirs had consolidated their power, and Jesus, Joseph and Mary could return home. The second of February was the fortieth day since the visit of the wise men and is the traditional date (early Christian tradition, that is, not modern) for the return from Egypt.

Joshua's long day

In Geocentricity,3 the date for Joshua's long day is derived to be May 12, 1448. The derivation is based on the dividing line between night and day when compared with the world-wide tales of a long day, a long night, and a long sunset. So that date is actually in our modern, Gregorian calendar. Now it so happens that going backwards in time, this program switches automatically from the Gregorian calendar (the calendar we now use, which started on October 15, 1582) to the Julian calendar (the calendar which was previously in use). The Julian calendar ended on October 4, 1582, so there was no October 5th through the 14th in 1582. That is, October 4 was followed by the 15th in 1582. This change was made because the seasons were migrating through the calendar. For example, the first day of spring is traditionally March 21 (actually, it's closer to March 20.5). That was the case when the Julian calendar (named after Julius Ceasar) was instituted. By 1582, however, the first day of spring had drifted to March 31 and was about to go into April. Hence the change in calendars.

What this means is that we have to convert the date for Joshua's long day from Gregorian to Julian calendars in order to find the correct day of the week and phase of the moon. To do this we run the program for the Gregorian date, namely, we enter the line:


when the program asks for the date. The screen then displays the following information:

In the year 1448 B.C. (-1447 ) May 12 was on a Sunday
The first day of spring was on April 1.5
The first day of summer was on July 3.3
The first day of fall was on October 4.9
The first day of winter was on January 2.8
Lunar data:
The moon's age from new was 12 days.
Distance from earth is 58 earth radii
Ecliptic latitude and longitude are -1° and 176°

The only thing we care about at this time is the date for the first day of spring. It is April 1.5. Today the first day of spring is March 20.5. The difference is 12 days. So in 1448 B.C. the first day of spring is 12 days later than in the Gregorian calendar. Hence, we must add 12 days to the desired date. This makes the date May 24, 1448 B.C. Running the program with that date gives us:

In the year 1448 B.C. (-1447 ) May 24 was on a Friday
The first day of spring was on April 1.5
The first day of summer was on July 3.3
The first day of fall was on October 4.9
The first day of winter was on January 2.8
Lunar data:
The moon's age from new was 24 days.
Distance from earth is 61 earth radii
Ecliptic latitude and longitude are 2° and 345°

This raises some interesting points. First, note that the event happened on a Friday, the day before the sabbath. Since the Israelites were to rest on the sabbath, it was imperative that the battle be closed before sunset. Second, note that the moon's age is 24 days. This is a couple of days after last quarter. This position for the moon is in agreement with the Egyptian account of Joshua's long day presented in Geocentricity, and it explains why there seem to be no folk tales of a stoppage of the moon. We have stories of a long night, but not of the moon stopping and hovering in the heaven. At this phase of the moon, except for a strip over West Africa, mostly over the Sahara Desert, all areas of the world experiencing a long night are moonless. Are any of our readers, particularly, African readers, aware of any tales of the stopping of the moon?


A program which gives the ability to compute the day of the week plus the phases of the moon for any given date can be a powerful help in organizing and studying dates and events in the Bible. We have found some intriguing information and timings. It is our hope that the program will be widely distributed.


1 ”A Planetary Alignment at the Creation?” Biblical Astronomer, 3(64):23, Spring 1993.

2 The dates marking the start of the seasons are good to within about half-a-day, as can be checked by running the program with known dates in the twentieth century. Compare the mean solar longitude, which is a degree or two lor for the first day of spring, pretty close for the first day of summer, two or three degrees too high for the first day of fall, and a degree or so too high for the first day of winter.

3 Bouw, G. D., 1992. Geocentricity, (Cleveland: Association for Biblical Astronomy), pp. 75-76. See back cover of this issue for availability.

Updated on 6 January, 2005 by GDB