3. The Hebrew Calendar

Genesis 1:14-18, "And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for and for days, and years . . . . And God made two great lights; the greater light for the rule of the day and the lesser light for the rule of the night; He made the stars also."

The Hebrew word for seasons "moed" is used in Leviticus 23 in describing the seasons of festivals of the Lord. Sun is defined as the ruler for the day and the moon as the ruler for the night. The moon is the "lesser light," being in itself not luminous, but reflect the light of the sun.

God is the "Sun of Righteousness," (Malachi 4:2). Men created in the image of God is like the moon, reflecting His glory. The first of God's material creation was light (Genesis 1:3 ) and Sun itself was created later out of the primeval light material. The purpose of creating the Sun and the moon were to produce seasons and days in cyclic fashion. This defines countable time. Time cannot be measured without repeating cycles. What vary are the cultural values and goals that dictate which cycles are significant. Time is the qualitative aspect of matter in motion. Change is what gives the feeling and concept of time. If nothing change, time cease to exist. A linear change however gives us the notion of time with its changes, but it will give no means of measuring time. Our grandmothers quoted time in terms of what happenned at some point in time. "I got married when the wheat turned brown". Many historians marked the time in terms of eclipses. But they are only markers and cannot measure time. All measurement of time requires repeating cyclic changes. Bible says that the motion of sun and the moon were made for this specific purpose. They were indeed the basis of all calendars.

Einstein said, "Space and time are modes by which we think, not conditions under which we live." Time--the time that we know through clocks and calendars--were invented as an extension of the cyclic motion. This is because we can count time only when we have a cycle which becomes the unit of time.

Genesis 7:11 states, "In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened."

This is the first time the Bible mentions a Calendar. Evidently Noah was familiar with the calendar. So Noah knew of day as defined by the setting and rising of the sun. He knew of the month in terms of the waxing and vaning of lunar phases. The seasons provided the measure of years. This gave Noah the measure of time and he started his year from his birth which formed the marker origin. The flood then became the next marker. He could measure the cycles that passed in years, months and days between the two events.

Calendars of all cultures have their basis on the basic solar and lunar orbital motions. The day is based on the rotation of the Earth on its axis, the year is based on the revolution of the Earth around the Sun, and the month is based on the revolution of the Moon around the Earth. The problem however is that all these three cyclic movements are independent of each other and are not correlated to form an integral whole.

The tropical year is defined as the mean interval between vernal equinoxes; it corresponds to the cycle of the seasons However, the interval from a particular vernal equinox to the next may vary from this mean by several minutes.

The synodic month, the mean interval between conjunctions of the Moon and Sun, corresponds to the cycle of lunar phases Any particular phase cycle may vary from the mean by up to seven hours. A calendar year do not form an integral number of months or of days to synchronize with the tropical year. The Solar year is 365.242199 days and the lunar month is 29.53059 days. Here was the basic problem. It would have made life easier if the number of days in a month was an exact integer and the number of months in an year was an exact integer. But unfortunately it is not so. So we get the complications of calendar. This therefore required experts to keep calendars. By traditions it was the priests in all cultures who maintained this calendar science.

The Gregorian Calendar with which we are familiar with is a solar calendar. To do so, days are intercalated (with leap years) to increase the average length of the calendar year. Islamic calendar is a lunar calendar, and follows the lunar phase cycle without regard for the tropical year. This is essentially desert calendar where solar seasonal variations are not reflected accurately. The Hebrew calendar on the other hand is a lunisolar calendar, has a sequence of months based on the lunar phase cycle; but every few years a whole month is intercalated to bring the calendar back in phase with the solar year. This reflects the agricultural and nomadic animal husbandry cultures in coexistence.

In 1967, the definition of a second was officially divorced from the Earth's rotation, motion of the moon and of the sun and of the position of the stars. That year, the 13th General Conference of Weights and Measures redefined the second as "9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom when free from all external fields." It is now defined in terms of the basic nature of light as a wave motion. However scientists had to identifiy the particular light in objective terms tied to matter (Isolated Cesium 133 atom)

Hebrew Calendar

The Hebrew calendar as we know today was codified into a cogent system and given to all men by Rabi Hillel II in AD 359 The science of calendar calculations were a secret science and were known only to the priestly class. This publication was forced upon the Jewish authorities because of historic reasons.

"Up to the middle of the 4th century C.E., the Palestinian patriarchate retained the prerogative of determining the calendar, and guarded the secrets of its calculation against the attempts of the rapidly advancing communities in Babylonia to have a voice in its determination. It was not until after [false] Christianity had become dominant in the Roman Empire [under Constantine], and the Christian rulers forbade the Jewish religious leadership to proclaim leap years or to communicate with the Jews outside the empire, that it was determined to abandon the method of official proclamation of months and years and to fix the calendar in permanent form. The patriarch Hillel II, in 359, decided to publish the rules for the calculation of the calendar, so that all Jews everywhere might be able to determine for themselves and to observe the festivals on the same day. From that time on the Jewish calendar has been stabilized."
Universal Jewish Encyclopedia

In most cultures (as in Egypt and India) this was used as a tool of asserting the superiority of Priestly class over laymen. This practice must have been a carry over from the Egyptian tradition for the Hebrews. Egyptian agricultural calendar based on the Nile's annual flooding and consequential delta agriculture evidently influenced Hebrew calendar. During the nomadic period when animal husbandry was the method of livelihood, the cycle of mating and breeding were important and these also influenced the Hebrew calendar. Levitical calendar of the festivals therefore included all these. Later during the Babylonian exile, Israel came in contact with sophisticated Calendars and Astronomical Clocks (sixth century B.C) which again influenced the Hebrew calendar as is known today. .

During the pre-exilic period the Temple Sanhedrin was in charge of the declaration of months and intercalations. The sightings of lunar crescent was the beginning of the month in the same style as it is practiced in the Islamic world . Molad (plural, moladot): "birth" of the Moon, is the birth of the month. Decisions on intercalation were influenced, if not determined entirely, by the state of vegetation and animal life which in turn are determined by the sun's motion. Dehiyyah( plural, dehiyyot) is the "postponement" rule by which the beginning of year is delayed until after the molad when required. Initally the month started strictly on sighting of the new moon. However as the science progressed some amount of interpolations by calculations were inevitable.

Based on the lunar sightings an ordinary (non-leap) year may contain 353, 354, or 355 days. A leap year with an additonal month may contain 383, 384, or 385 days. The three lengths of the years are termed, "deficient", "regular", and "complete", respectively. Deficient month (haser) has 29 days. Full (male) month has 30 days. If the sightings on new moon were not hindered by clouds then the defient and full months alternated in order.

An ordinary year has 12 months, but a leap year has 13 months. A year is a leap year if the number year mod 19 is (i.e if the year is divided by 19 gives a remainder of ) one of the following: 0, 3, 6, 8, 11, 14, 17

In a regular year the numbers 30 and 29 alternate; a complete year is created by adding a day to Heshvan, whereas a deficient year is created by removing a day from Kislev. The alteration of 30 and 29 ensures that when the year starts with a new moon, so does each month. Every month starts (approximately based on the sighting conditions) on the day of a new moon. The Sanheran alone had the sole authority of maitaining the calendar and autority to declare new month and year.

"The authority over the observation of the new crescent (and the subsequent proclamation of New Moon Day) was given not to everyone -- as is the case with the Sabbath day . . . which everyone counts 6 days and rests on the seventh day -- but only to the court [the Sanhedrin]. The day sanctified and proclaimed by the court as the beginning of the month was New Moon Day. For it is said: This month shall be unto you (Exodus 12:2), that is to say, accepting or rejecting evidence concerning this matter is put into your hands." :

" . . . the Jewish court, too, used to study and investigate and perform mathematical operations, in order to find out whether or not it would be possible for the new crescent to be visible in its 'proper time,' which is the night of the 30th day. If the members of the court found that the new moon might be visible, they were obliged to be in attendance at the court house for the whole 30th day and be on the watch for the arrival of witnesses. If witnesses did arrive, they were duly examined and tested, and if their testimony appeared trustworthy, this day was sanctified as New Moon Day. If the new crescent did not appear and no witnesses arrived, this day was counted as the 30th day of the old month . . . . If, however, the members of the court found by calculation that the new moon could not possibly be seen, they were not obliged to be in attendance on the 30th day or to wait for the arrival of witnesses. If witnesses nonetheless did appear and testified that they had seen the new crescent, it was certain that they were false witnesses, or that a phenomenon resembling the new moon had been seen by them through the clouds, while in reality it was not the new crescent at all."
Chapter 1, Paragraph 5-6
The Code of Maimonides, Book Three Treatise Eight, "Sanctification of the New Moon," translated by Solomon Gandz. Edited by J. Obermann and O. Neugebauer. Yale Judaica Series. New Haven, Yale University Press, 1956
Maimonides, wrote this treatise from 1173-1178 A.D., drawing from an Arabic authority, al-Battani.

Name	Deficient year (haser) is an year in which the months of Heshvan and Kislev both contain 29 days	Regular year (kesidrah) is an year in which Heshvan has 29 days and Kislev has 30 days	Complete year (shelemah) is an year in which the months of Heshvan and Kislev both contain 30 days
1. Tishri	30	30	30
2. Heshvan	29	29	30
3. Kislev	29	30	30
4. Tevet	29	29	29
5. Shevat	30	30	30
(Adar I Only on Leap year	30	30	30)
6. Adar	29	29	29
7. Nisan	30	30	30
8. Iyar	29	29	29
9. Sivan	30	30	30
10. Tammuz	29	29	29
11. Av	30	30	30
12. Elul	29	29	29
Total:	353 or 383	354 or 384	355 or 385

The month Adar I is only present in leap years. In non-leap years Adar II is simply called "Adar". Talmudic sources tell us that the calendar committee did not rely solely on calculation but on observation as well. They added a 13th month "when the barley in the field had not yet ripened, when the fruit on the trees had not grown properly, when the winter rains had not stopped, when the roads for Passover pilgrims had not dried up and when the young pigeons had not become fledged" (Arthur Spier, The Comprehensive Hebrew Calendar, p. 1).

. Irrespective of the length of the day and night due to variations in seasons, a day is divided into 12 hours and the night is divided into 12 hours. Thus an hour is not defined objectively. An Hour is divided into 1080 Halakim(singular, helek) parts. One helek is about 3 1/3 seconds. For calendar calculations, the day begins at our 6 P.M., which is designated 0 hours. Jerusalem is 2 hours 21 minutes ahead of Greenwich.

The calendar year begins with the first day of Rosh Hashanah (Tishri 1). This is determined by the day of the Tishri molad and the four rules of postponements (dehiyyot). The dehiyyot can postpone Tishri 1 until one or two days following the molad.

(a) If the Tishri molad falls on day 1, 4, or 6, then Tishri 1 is postponed one day.
(b) If the Tishri molad occurs at or after 18 hours (i.e., noon), then Tishri 1 is postponed one day. If this causes Tishri 1 to fall on day 1, 4, or 6, then Tishri 1 is postponed an additional day to satisfy dehiyyah (a).
(c) If the Tishri molad of an ordinary year (i.e., of twelve months) falls on day 3 at or after 9 hours, 204 halakim, then Tishri 1 is postponed two days to day 5, thereby satisfying dehiyyah (a).
(d) If the first molad following a leap year falls on day 2 at or after 15 hours, 589 halakim, then Tishri 1 is postponed one day to day 3.

Dehiyyah (a) prevents Hoshana Rabba (Tishri 21) from occurring on the Sabbath and prevents Yom Kippur (Tishri 10) from occurring on the day before or after the Sabbath.

Dehiyyah (b) is an artifact of the ancient practice of beginning each month with the sighting of the lunar crescent. It is assumed that if the molad (i.e., the mean conjunction) occurs after noon, the lunar crescent cannot be sighted until after 6 P.M., which will then be on the following day.

Dehiyyah (c) prevents an ordinary year from exceeding 355 days. If the Tishri molad of an ordinary year occurs on Tuesday at or after 3:11:20 A.M., the next Tishri molad will occur at or after noon on Saturday. According to dehiyyah (b), Tishri 1 of the next year must be postponed to Sunday, which by dehiyyah (a) occasions a further postponement to Monday. This results in an ordinary year of 356 days. Postponing Tishri 1 from Tuesday to Thursday produces a year of 354 days.

Dehiyyah (d) prevents a leap year from falling short of 383 days. If the Tishri molad following a leap year is on Monday, at or after 9:32:43 1/3 A.M., the previous Tishri molad (thirteen months earlier) occurred on Tuesday at or after noon. Therefore, by dehiyyot (b) and (a), Tishri 1 beginning the leap year was postponed to Thursday. To prevent a leap year of 382 days, dehiyyah (d) postpones by one day the beginning of the ordinary year.

We have seen that Hebrew calendar tries to fits in several cultural factors. There are four possible years permitted. The new year begins on:

A Hebrew-calendar day begin at sunset which is defined as when three medium-sized stars are visible to the naked eye. Sunset marks the start of the 12 night hours, whereas sunrise marks the start of the 12 day hours. This means that night hours may be longer or shorter than day hours, depending on the season.

Using the current Hebrew Calendar the creation took place AM 1 at 5 hours and 204 parts after sunset i.e. just before midnight on Julian date 6 October 3761 BC.

HEBREW MONTH	HEBREW NAME OF CONSTELLATION	GREGORIAN DATE
NISSAN	T'LEH	3/21 - 4/19
IYAR	SHOR	4/20 - 5/20
SIVAN	TEUMIN	5/21 - 6/20
TAMUZ	SARTAN	6/21 - 7/22
AV	ARI	7/23 - 8/22
ELUL	BETHULAH	8/23 - 9/22
TISHREI	MAZNAYIM	9/23 - 10/22
CHESHVAN	AKRAV	10/23 - 11/21
KISLEV	KESHETH	11/22 - 12/21
TEVETH	GEDI	12/22 - 1/19
SHEVAT	DELI	1/20 - 2/18
ADAR	DAGIM	2/19 - 3/20

The science of astrology and signs of zodiac came into Hebrew culture from other cultures. They do not form part of the Calendar as given from God.

The following is a listing of Biblical events according to their dates on God's calendar collected from Judaic sources.

1 Hezekiah opens doors of Temple and begins to repair it, II Chronicles 29:3, 17. Finished the work on the 16th.

1 Prophecy given to Ezekiel that Nebuchadnezzar, King of Babylon, would be given the land of Egypt, Ezekiel 29:17-20. Reaffirmed at a different time of the 7th day, Ezekiel 30:20-26.

1 God ordains a bullock to be sacrificed and the Temple to be cleansed, Ezekiel 45:18-19. Also to be done on the first day of the seventh month, verse 20.

1 Ezra decides to leave Babylon for Jerusalem with the intent of seeking God's law, doing it, and teaching God's statutes and judgments to Israel, Ezra 7:6-10. Departs on 12th day, Ezra 8:31.

13 Haman's death sentence against the Jews was posted in the kingdom of Persia, Esther 3:12-13.

24 Daniel had been fasting for three weeks, is given understanding by an angel, Daniel 10:2-4.

X Israel came into desert of Zin, abode in Kadesh; Miriam died there, Numbers 20:1.

1 Eternal spoke to Moses in wilderness of Sinai on second year after they were come out of Egypt, Numbers 1:1. All Israel from twenty years old assembled together, verse 18.

2 Solomon begins to build the Temple in the fourth year of his reign, II Chronicles 3:2.

15 Feast of Unleavened Bread kept in second month by Hezekiah, II Chronicles 30:13, 21-23.

17 Fountains of deep broken up, 40 days of rain begin the Noachian Flood, Genesis 7:11.

20 Cloud taken up, Israel begins journeying from Sinai in the second year of the Exodus, Numbers 10:11.

X Foundations of the temple laid by Zerubbabel, Joshua and others returned from captivity, Ezra 3:8-13.

1 Again, God gives Ezekiel a prophecy as to Egypt's fall, but that their conquerors the Assyrians will fall likewise, Ezekiel 31:1-18.

23 Haman, enemy of the Jews, hanged. King of Persia's letter went out allowing Jews to defend themselves against their enemies on Adar 13. Mordecai advanced, Esther 8:1-17.

X Pentecost, a Holy Day, always falls on second day of the week, can be on 7th, 9th, 11th, or 13th of third month.

X Asa and other faithful of Israel enter into a covenant with God, II Chronicles 15:10, 12.

5 God begins to work through Ezekiel, gives him visions and prophecies, Ezekiel 1:1-2.

9 Besieged by King Nebuchadnezzar of Babylon, there was sore famine in Jerusalem, and the city was broken up about 586 B.C., Jeremiah 39:2; 52:6-7; II Kings 25:3. Jews remembered this horrifying event by commemorating it with a fast, Zechariah 8:19.

1 Aaron died on Mount Hor in the fortieth year of Israel's wandering, Numbers 33:38. Israel mourned for thirty days, Numbers 20:28-29.

7 Babylonian army burns the Jerusalem temple, King's palace, and all the houses of Jerusalem, takes most of the rest of Judah captive, Jeremiah 1:3; 52:12-16; and II Kings 25:8-12. Jews commemorated this sad event with a fast, Zechariah 8:19 on tenth day. God was wrathful with their corrupted manner of fasting, Zechariah 7:1-13.

10 Certain elders of Israel come to inquire of the Eternal before Ezekiel. He is given a message from God that the reason they are in captivity is that they have polluted God's Sabbaths, Ezekiel 20:1-49.

5 Ezekiel is given a vision from God, sees several abominations being committed by God's people, Ezekiel 8.

24 The Eternal stirs up the spirit of Zerubbabel, Joshua and the remnant of the people to do the work of the building of God's House, Haggai 1:14-15.

13 Publishing of Haman's death sentence upon all the Jews in captivity, Esther 3:10-13.

14 (& 15) Purim, celebration of Jews' deliverance from Haman's death decree, Esther 9:1-32.

25 (27) Evil-merodack, King of Babylon, released former King Jehoiachin of Judah from prison and gave him a daily allowance for the rest of his life, II Kings 25:27-30; Jeremiah 52:31-34.

SEEDTIME	15 TISHREI to the middle of KISLEV
WINTER	15 KISLEVto the middle of SHEVAT
COLD	15 SHEVAT to the middle of NISSAN
HARVEST	15 NISSAN to the middle of SIVAN
SUMMER	15 SIVAN to the middle of AV
HEAT	15 AV to the middle of TISHREI

Hebrew Calendar

Determining Tishri 1

Reasons for the Dehiyyot delay are: