Following the biblical calendar would be easy if it wasn’t based on the moon. Since the cycle of the moon does not quite fill out a solar month, and twelve lunar cycles do not quite fill out a solar year, the calendar slowly shifts over time.

Without occasional correction, we would soon be celebrating Passover in December. Every so often, the Jewish calendar compensates by adding an extra month and thereby shifting everything back.

From time to time, teachers in the Hebrew Roots movement attempt to persuade people to abandon the Jewish reckoning of the biblical calendar and adopt an alternative calendar based upon the ripening of barley or other measure of the seasons. They argue for a stricter and more consistent correlation between the phase of the moon and the date of the month than the Jewish version of the biblical calendar offers. They advocate an alternative reckoning of the calendar on the basis that they perceive their interpretation to be more biblically correct. But is it?

Biblically Correct Calendars

From my reading of the Bible, the more biblically correct thing to do is to defer to Jewish authority. The Bible says that when debates over the application of a commandment of the Torah arise, we are to default to the Jewish authorities (Deuteronomy 17:8-13). A debate over the reckoning of the calendar falls into this category.

When introducing the appointed times of the biblical calendar, the LORD said to Moses, “Speak to the people of Israel and say to them, these are the appointed feasts of the LORD that you shall proclaim as holy convocations; they are my appointed feasts” (Leviticus 23:1-2). The words “that you shall proclaim” are understood to be directed to the Jewish authorities. The authorities over the Jewish community have the biblical responsibility of proclaiming the festivals, i.e., announcing the annual festivals and fixing their dates. It’s their job to proclaim the new moons, the new months, and the dates of the festivals. God instituted and ordained the seventy elders over Israel (the Sanhedrin) and the Jewish courts of authorities that decided on the reckoning of the calendar:

Let every person be subject to the governing authorities. For there is no authority except from God, and those that exist have been instituted by God. Therefore whoever resists the authorities resists what God has appointed, and those who resist will incur judgment. (Romans 13:2)

Observing the New Moon

The responsibility for determining the calendar was the first commandment that God gave the nation of Israel when he said to Moses and Aaron, “This month shall be for you the beginning of months. It shall be the first month of the year for you” (Exodus 12:2). The Bible commentator Rashi reckoned Exodus 12:2 as the Torah’s first formal mitzvah (commandment) because it was the first commandment that God gave specifically to the nation of Israel. He noted that the LORD delivered the commandment directly to Aaron and Moses, the leaders of the generation. That is, he gave the leadership the authority to declare the beginning of a new month and determine the biblical calendar.

In the days of the Bible, the people of Israel determined the calendar based upon the sighting of the Rosh Chodesh moon. Sighting of the moon depends upon subjective observations, circumstances, and weather conditions—variables that could lead to multiple opinions about when the new month had begun. In order to keep the whole community on the same day of the month, the nation needed a system of consensus for determining the calendar. Otherwise, those who lived in different areas or who may have been less careful in their observations of the sky would fall out of synchronization with the rest of the people.

This issue becomes critical when attempting to keep commandments that pertain to specific dates. For example, in Exodus 12, God gave the whole community of Israel several date-specific commandments. Consider the situation with the Israelite community in Egypt. If one group of Israelites believed that the new moon should be calculated differently than the majority, or if another group had missed sighting the moon the first night and therefore lagged behind the calendar by a single day, disaster would have ensued. The splinter groups would have failed to mark their houses with the blood on the correct night. The mistake would have cost them their firstborn sons.

The LORD precluded that possibility when he spoke to Moses and Aaron saying, “This chodesh (renewal of the moon) shall be the beginning of months for you” (Exodus 12:2). He thereby determined the first day of the month, synchronizing the community’s calendar:

God showed Moses the moon in its first crescent (chodesh) and said to him, “When the moon renews itself like this it will be the beginning of the month for you.” (Mechilta 1)

Declaring the New Month

The Mishnah describes the ceremony whereby the Sanhedrin used to declare the new moon. Witnesses who sighted the crescent of the new moon traveled immediately to the Sanhedrin. The members of the Sanhedrin cross-examined the witnesses to ensure that they had definitely seen the new moon. Then they declared, “It is sanctified.” They alerted the rest of the nation by means of signal fires and messengers who spread out through the land and through the whole Diaspora.

The commandment to determine the new moon grants the authority to determine the biblical calendar, fix the appointed times, and ascertain the dates for celebrating the biblical festivals. Does the Torah grant that authority to everyone? Is every individual or every individual synagogue, congregation, and community responsible for determining the biblical calendar? If so, no forum for unity could be established, and every person could determine his own calendar according to his own interpretations. Different congregations and communities would fight over the “correct” day for celebrating festivals, and the sanctity of the holy days would be trampled in the mud. Some communities would be celebrating their break-fast at the end of Yom Kippur while others were just beginning the fast. Some would celebrate a month earlier than others. We would fight and argue, breaking the prohibition to “avoid foolish controversies … and strife and disputes about the Torah,” which are “unprofitable and worthless” (Titus 3:9). Therefore, the responsibility of determining the calendar does not fall to us; it falls to the established and recognized leadership of the entire nation of Israel. In the days of the exodus, that was Moses and Aaron.

The Calendar in the Apostolic Period

In the days of the apostles, the Sanhedrin had the authority to determine the calendar.

In the Apostolic Era, various splinter groups such as the Essenes determined their own calendars independently of the Sanhedrin, but in so doing, they severed themselves from the broader community of Israel and made themselves irrelevant. Yeshua and the apostles, however, followed the calendar established by the Jewish authorities in Jerusalem and thereby celebrated the festivals along with the rest of nation. If that was not the case, the New Testament would have made note of the deviation.

No King in those Days

Some modern Karaites and Hebrew Roots enthusiasts have opted to return to sighting and determining the new moon. Others have adopted more astronomically correct models of the lunar calendar, thereby fulfilling the verse that says, “In those days there was no king in Israel; everyone did what was right in his own eyes” (Judges 21:25).

Each person may do as he sees fit, but to the same extent that we develop calendars independent of the rest of the Jewish people, we sever ourselves from fellowship and community with the Jewish people and one another. If we truly believe that God’s appointed times are indeed his appointments given to Israel, then we should celebrate those appointments along with all Israel and on Israel’s authority, not independent of the greater people of God.

The Fixed Calendar

In the fourth century, the Christianized Roman government wanted to stop Christians from observing Passover according to the Jewish reckoning of the calendar. They forbade the Sanhedrin from convening and determining the new moon. The Jewish communities throughout the Diaspora began to determine the calendar independently of one another. Chaos, discord between communities, and disunity resulted. A cloudy day could change the date of Passover. Without a central authority to intercalate an extra month, the seasons began to slide. In a few years, Passover would be falling in December.

To remedy the situation, Rabbi Hillel II used astronomical projections and mathematical equations to create a fixed calendar that all Israel could use to keep the months and festival season synchronized without relying on observation of the moon. We still use Rabbi Hillel’s calendar today. Until a Sanhedrin wielding civil and religious authority over all Israel convenes and alters the arrangement, the calendar of Rabbi Hillel II remains the official standard for determining new moons, biblical months, and the biblical festivals. No rabbi, leader, or group of leaders has the authority to alter what has been set in place by the leadership of Israel. Any persons who attempt to do so can be dismissed because they assume authority that does not belong to them.

The fixed calendar is not a perfect system, and occasionally discrepancies arise between the Jewish calendric date and the actual phase of the moon, and occasionally it might seem that the extra month could have waited another year, but the fixed calendar provides a universal standard set in place by the lawful and recognized authorities over Israel. It needs to suffice until a singular authority over all Israel arises that can correct it. This will happen soon when the soles of our Master Yeshua’s blessed feet rest again upon the Mount of Olives. In that day, he may reinstate the commandment of declaring the new moon by means of observation, or he may declare the new moons himself.

Source: First Fruits of Zion