- Month: the 1st day of the month begins with the 1st sunset in Jerusalem on or after the astronomical new moon.
- Year: spring harvest begins by the 1st Sunday following the 14th day of the 1st month.
Defining the Month and Year
The timing of God’s calendar each year depends upon a monthly date, such as the 14th day of the first month. So, in order to know when to celebrate a feast of the Lord, we first need to know when a month begins, and we also need to know when a year begins.
There are several types of annual calendars in use today, and also several different ways of defining a month. Only one of these combinations may be correct, and it is theoretically possible that none of them are exactly correct.
We suppose that God revealed His calendar definitions to Man very early in history and that Man has in large measure presumed to deviate from God’s way. We therefore wish to look to God’s instruction, as best we can, to determine His calendar, and expect that what we find might is very different from any calendars in use today: it may not have much support from either tradition or history. Though God does not tell us exactly how He does this in Scripture, He does provide some very strong clues.
Psalm 104:19a says, “He appointed the moon for seasons,” where seasons is the same word (mo ed) translated feasts in Leviticus 23:4. We can see from this that God uses the moon to define His feasts, so the phases of the moon must be critical in defining a month.
Both the first and last feasts are weekly feasts that begin on the evening between the 14th and 15th day of the month, about the time of the full moon. The moon will be the fullest (and therefore a sign of) at the start of these key feasts if the dark moon (the lunar conjunction, the astronomical new moon), is within the last day of the month. We therefore define the month as follows: the new month begins at the first sunset in Jerusalem on or after the astronomical new moon. Relevant dates and times for Jerusalem are: New Moon, Sunset.
Next we consider a biblical definition for a year. The new year is defined by the month containing Passover (Ex 12:2-3), since Passover is immediately followed by Firstfruits (the first Sunday after the 14th day of the first month), a feast which requires that an offering of newly harvested grain be presented to God. A new year should therefore start with the month in which the spring harvest is expected to begin by the time this grain offering is due. (Le 23:10-14) This convention consistently synchronizes the solar and lunar cycles (the Gregorian calendar uses varying month lengths and a leap year to do so). This implies that the earliest expected spring harvest time in the vicinity of Jerusalem will define the new year.
Many orthodox Jews follow a rabbinic calendar which has little resemblance to the biblical calendar. For example, the rabbinic calendar celebrates the New Year, Rosh Hashanah, in the Fall on the feast of Trumpets, whereas Torah states that Passover is in the first month, which is in Spring. The rabbinic calendar was developed early in the Diaspora so that Jews world-wide could observe the feasts as a global community when they were unable to either communicate across long distances or conveniently return to Jerusalem. Now that technology enables an instant global awareness of the required biblical parameters for determining the calendars, some Jews, the Kararites, have returned (for the most part, at least) to a biblical definition.
For millennia, visible sighting of the crescent moon, which follows shortly after the new (dark) moon, has been used by many cultures, including the Hebrew during the time of Yeshua, to mark the beginning of the month. Yet the Chinese have always used the new moon, so we know that it is not an impractical method.
In theory, the consistently predictable behavior of the moon allows anyone who is paying attention and carefully observing the moon phases over time to determine monthly boundaries with reasonable precision, so it simply remains to look to Scripture to determine which phase should be used to mark the start of a month.
In support of the crescent moon, some argue (from Ex 12:2) that when God was instructing Moses in the observation of Passover, that God must have been speaking to him on the 1st day of the month and that the moon must have been visible to Moses at the time. This assertion appears arbitrary since God would likely have used the very same language to describe the first month of the year if He had been speaking with Moses and Aaron on the third or fourth day of the month, or if the moon was not visible. There isn’t any hint in the text that God was speaking to them on the first day of the month.
The Hebrews may have begun using the visible crescent while captive in Babylon (~ 600 BCE). We do not know of any records, scriptural or otherwise, indicating that they used the crescent moon prior to their first captivity.
Using the visible crescent to define the month may seem impractical when the moon is not visible, such as when it is very cloudy or there is a sand storm, etc., resulting in potential confusion even within a relatively small geographic area. In such situations the ancients would just end the month after 30 days regardless of a sighting, knowing that a month cannot be more than 30 days long.
The reasoning to start the month with the crescent appears no more logical than to end the month with the crescent. It seems that the only argument in favor of the crescent is historical precedent.
Some propose to start the month with the full moon. The strongest argument against this view appears to be that in a time when the Jews used the visible crescent Yeshua observed Passover and was crucified as the Passover Lamb in the same general time period that the Jews celebrated this feast. If the full moon begins the month then Yeshua did not celebrate any of the biblical feasts correctly, nor did He fulfill any of them in their actual appointed seasons, in which case we must simply ask: Why bother being precise about the calendar at all then?
How to use the new moon to define the monthly boundary:
♦ Using God’s definition of a day, which begins in the evening, or with fading light and then darkness (Ge 1:5, Le 23:32), does not seem relevant to the definition of a month, as if we could apply this principle in a monthly definition. Technically, since there is actually a small invisible crescent just before and just after the conjunction, we generally have both a waning gibbous and a waxing crescent on the same day. And in a practical sense, the moon is not significantly visible to the naked eye for multiple days so the month will begin and end in relative darkness. It seems then that the monthly definition should be established on different grounds than the definition of the day.
♦ The conjunction is a specific instant in time marking a key boundary condition in the lunar cycle, so this event is a natural one to use to mark the monthly boundary.
♦ If the new moon is used to mark the monthly boundary, since it happens at a particular instant in time that rarely coincides with a daily boundary, the conjunction must either occur within the first or last day of the month.
♦ The two weekly feasts, Unleavened Bread and Tabernacles, both start on the 15th day of the month, and since the moon is given to define the seasons, or the appointed times for God’s feasts, it seems that the evening when the moon is fullest should mark the beginning of these feasts. Ps 81:3 states: “Blow up the trumpet in the new moon, in the time appointed, on our solemn feast day.” The phrase in the time appointed is the Hebrew kehseh which means fullness, evidently relating the demarcation of God’s appointed times by the full moon. The text is evidently not describing a single day on which to blow the trumpets, but the various occasions on which they were to be blown, such as the first day of the month, on solemn days such as Atonement, and on times appointed for feasting marked by the full moon, such as Passover and Tabernacles. (Nu 10:10)
♦ Since the time from the conjunction to the full moon is 14.75 days, placing the conjunction in the last day of the month places the full moon between days 14 and 15 in such a way that the full moon can be used as a sign to mark the beginning of the spring and fall weekly feasts (which both begin the evening between days 14 and 15). People watching the moon closely will be confirmed by the sign of the full moon that it is time to begin the feast. However, placing the conjunction in the first day of the month places the full moon one day after the start of both of these feasts so in this convention the moon isn’t functioning as well as a sign by which to announce the start of the feast.
Kararite dates vary slightly from ours since they use the visible crescent.
Exactly how to apply the biblical definition of the new year by determining whether the harvest is mature enough to offer the appropriate grain sacrifice is unclear. Evidently, God was leaving this up to the judgment of seasoned farming communities who understood when to harvest their grain. However, today many try to make this determination who are ignorant of agrarian life and methodologies, creating much confusion and division.
Those who wish to avoid this imprecision altogether and take the human element out of the equation use the vernal (spring) equinox to determine the new year. The benefit in using this is that it is predictable and independent of the growing season. People in the land that needed to travel to Jerusalem for Passover could plan appropriately, and if there happened to be a famine in the land corrupting the springtime harvest then the New Year was unaffected. The drawback in using such a method is that if it ever failed to define the new year such that Firstfruits fell at the start of the Spring harvest in the vicinity of Jerusalem then it would contradict God’s instructions for this feast.
The fact that God’s calendar is oriented around the activity of Earth, and even depends upon the discernment of Man, is interesting indeed and ought not to be lightly overlooked. It is not without biblical precedent that Paul affirmed God’s servants are “workers together with him.” (2Co 6:1) Further, if Israel was disobedient in following God’s Law then it might be entirely appropriate that a famine sent to chasten them would prevent the proper observation of these feasts.