The Turkey and the Menorah

Jacob Schor, ND, FABNO

October 15, 2013


Chanukah comes early this year; the first day falls on Thanksgiving. According to the Washington Post, this last happened in 1888.  The next occurrence will be in 79,043 years.


This rare overlap of holidays leads one to consider the calendars used to track the years.   The chaos created by the differing lengths of the solar and lunar years brings  William Paley, the English philosopher, to mind.  Born in 1742, Paley is remembered for his book Natural Theology, in particular for his ‘watchmaker argument’ for the existence of God. This argument states that design implies a designer and is the center of the modern ‘intelligent design’ movement. His argument is simply that if you found a watch on the road, you would assume that somewhere there is a watchmaker. Let’s put the theology aside for the moment and focus on this metaphor of God as a watchmaker.  If you found a watch that keeps time poorly, what does that say about the watchmaker?


There are three basic ways to track the passing of time- the rotation of the earth, the revolution of the moon around the earth and the revolution of the earth around the sun;  days, lunar months and solar years.


A careful watchmaker might have arranged these things with just a tad more precision. 


A lunar month is 29.5305888531 days long. There are 12.36826639275 lunar months in a year.


Thus 12 lunar months are 10.8751234326 days short of a year.


The study of calendars, astronomy, mathematics and physics, all start as an attempt to figure out how to sort out this fundamental discrepancy between a lunar  and  solar year. 


The Egyptians simply skipped using the moon and adopted a completely solar calendar.  Their need to accurately predict the date of Nile River’s annual flooding was likely behind this decision. The Egyptian year had twelve months, each thirty days long; the five days leftover at the end were used to celebrate the birthdays of various Egyptian gods.


The Greeks made some clever advances in counting their days.  In 432 B.C., Meton of Athens somehow realized that 235 lunar months were almost exactly equal to 19 years (the discrepancy is about 2 hours) and proposed a 19-year cycle of calendar counting. A century later, 332 BC, Calippus, figured out that 940 lunar months equals 76 years, each of 365.25 days. Hipparchus, the father of modern astronomy, pushed it even further, suggesting a calendar made of 304 years equal to 3760 lunar months and 111,035 days.  While they were onto something, these calendar systems never caught on.


Julius Caesar rejected the lunar month completely and decreed a system that followed the solar year alone giving no attention to the cycles of the moon.  It was Caesar who introduced the four-year leap year that we still use today, adding an extra day to February.  Aside from some minor adjustments made by Augustus Caesar in about 4 BC, this Julian calendar remained intact until 1582.


In that year, at the Council of Trent, Pope Gregory XIII issued an apostolic letter that adjusted how the calendar works, which corrected some discrepancies that had slipped in over the centuries.  In 1582, ten days were simply skipped; Thursday, October 4th was followed by Friday October 15th.  Thus we have just passed the 482nd anniversary of the ten days during which nothing happened.


To fine-tune the calendar, three leap years are omitted every four centuries. Every centurial year, not divisible by 400, lost its leap year.


This Papal proclamation made 400 years equivalent to 146,097 days, making the average calendar year 365.2425 days long, just 26.8 seconds longer than the actual year.


In contrast to this Julian-Gregorian Calendar, the Islamic calendar is based solely on the phases of the moon.  The Islamic year contains twelve lunar months. Being only 355 days long, Islamic dates move around the seasons in a cycle of about 33 years. Each year, in the Islamic calendar, the seasons begin 10 or 11 days later than in the previous year. A new month does not start until a reliable witness sees the new crescent moon. Astronomical calculations of when the New Moon should appear don’t count; the crescent itself must be seen.  This is why the crescent moon is so fundamental to Islamic imagery.



The modern Jewish calendar, technically a “fixed arithmetic lunisolar calendar,” has been in place since 1178. This calendar repeats in a 19-year cycle of 235 lunar months, with an extra lunar month added once every two or three years, for a total of 7 times per 19 years. So while we Jews follow lunar months, they shift occasionally to stay in accord with the solar year. As a result, Jewish holidays rattle about the calendar, but remain at about the same time of the year.  Chanukah, usually an early winter holiday, is usually in December to early January, sometime even after Christmas.  This year’s early date, overlapping Thanksgiving will be a once in a life-time experience. 



There are advantages to following a solar calendar and ignoring the lunar cycles, yet certain aspects of our physiology may still be influenced by the phases of the moon. 


It has long been believed that the phases of the moon affect timing of menstruation.


A July 2013 paper attempts to counter this belief.  In a study of 74 women with 980 menstrual cycles over a full calendar year, no synchrony was found between lunar phases with the menstrual cycle. [1]   


This hasn’t always been the case;  a 1980  paper did report significant synchrony. [2]  A 1986 paper that followed  826 women also reported synchrony; a significantly higher percentage of women menstruate during the new moon. [3] 


Is this newer 2013 study more accurate or have women changed over the last 30 years?  With greater exposure to brighter indoor and outdoor lighting, does the moon have less impact on our lives?


A 2006 Swiss study reported that we don’t sleep as well when the moon is full.  Using subjective reports from sleep diaries, participants reported sleeping about 20 minutes less per night when the moon was full and feeling more tired in the morning after a full moon. [4] 




There is also debate about whether the phases of the moon influence violent behavior.  A 2009 paper from Newcastle, Australia suggests that they do: 

“Of 91 patients with violent and acute behavioural disturbance, 21 (23%) presented during the full moon--double the number for other lunar phases (P = 0.002). Sixty (66%) had either alcohol intoxication or psychostimulant toxicity, and five attacked staff …… In contrast, 512 hospital security calls for patients with less severe behaviour were evenly distributed throughout the lunar cycle.”[6]


Yet a German study published also published in 2009 found no association for violent behavior with the phases of the moon. [7]   Could there be less exposure to moonlight  in Germany than Australia and could this explain these differences?


This is the theory put forth in a 1999 paper to explain why there is less impact and fewer psychotic breaks during full moon than once was the case; it is the brighter artificial outside illumination. [5]


The reasonable assumption has been that it is the light from the moon that accounts for the moon’s effect on people.  Thus a study by Cajochen et al published August 5 in Current Biology gives us pause.  Christian Cajochen and colleagues combined data collected over a period of years on 33 people who spent days sitting in bed under constant dim light.  They had no exposure to outside light, sunlight or moonlight. The researchers report that it took significantly longer for participants to fall asleep and that the slept less time and less deeply during a full moon. [8] 


The scientists were actually reluctant to publish these findings.  In the words of lead author Christian Cajochen,  “If you publish lunar stuff, you are going to be put in the ‘lunatic’ corner and not be considered a serious sleep researcher.”[9]


If sleep is effected by the full moon without visual cues, that leaves us two possibilities, either the body can sense the full moon by some internal mechanism that would feel its pull akin to the way the ocean’s tides are moved or that there is some internal clock, perhaps related to our circadian rhythm, that tracks the phases of the moon and doesn’t need so sight the moon to know its phase.  Either explanation is intriguing though most scientists if forced will opt for the later theory.


It is only in recent years that we have understood that degree of harm disruption of the circadian rhythm can be to a person’s health.  We aren’t even sure whether the body does track the lunar cycle.  Many would argue that not only that it does but that it may be equally important to our health. 


No matter what calendar we use to arrange our lives by, perhaps we should still step

outside now and then to take a look at the moon.







1. Ilias I, Spanoudi F, Koukkou E, Adamopoulos DA, Nikopoulou SC. Do lunar phases influence menstruation? A year-long retrospective study.  Endocr Regul. 2013 Jul;47(3):121-2.


2. Cutler WB. Lunar and menstrual phase locking. Am J Obstet Gynecol. 1980 Aug 1;137(7):834-9.


3. Law SP. The regulation of menstrual cycle and its relationship to the moon. Acta Obstet Gynecol Scand. 1986;65(1):45-8.


4. Röösli M, Jüni P, Braun-Fahrländer C, Brinkhof MW, Low N, Egger M. Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep. J Sleep Res. 2006 Jun;15(2):149-53.


5. Raison CL, Klein HM, Steckler M. The moon and madness reconsidered. J Affect Disord. 1999 Apr;53(1):99-106.


6. Calver LA, Stokes BJ, Isbister GK. The dark side of the moon. Med J Aust. 2009 Dec 7-21;191(11-12):692-4.


7. Biermann T, Asemann R, McAuliffe C, Ströbel A, Keller J, Sperling W, Bleich S, Kornhuber J, Reulbach U. Relationship between lunar phases and serious crimes of battery: a population-based study.  Compr Psychiatry. 2009 Nov-Dec;50(6):573-7.


8. Cajochen C, Altanay-Ekici S, Münch M, Frey S, Knoblauch V, Wirz-Justice A. Evidence that the lunar cycle influences human sleep. Curr Biol. 2013 Aug 5;23(15):1485-8. doi: 10.1016/j.cub.2013.06.029. Epub 2013 Jul 25.


9. Science News August 24, 2103 pg 15.