The Calendar That Christ Used

The Gregorian calendar hanging on your wall or refrigerator is used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas issued by Pope Gregory XIII, which introduced it as a modification of and replacement for the Julian calendar. But the LORD God gave the children of Israel a completely DIFFERENT calendar! And truly, without knowledge of this calendar, you CANNOT obey the LORD GOD!

Has the LORD God left it up to each individual to go by whatever calendar they choose? Have you ever thought about this? Sadly, most people don’t. Just like everything else in their religion ── they just assume that the calendar hanging on their wall (given to them by their insurance company) is a Christian calendar. Does the Lord GOD ── the very Creator of the known universe ── have His own calendar? And, has He actually preserved it for us today?

How is it possible that we ── true Christians ── know when to properly observe the Lord’s Passover, or the Days of Unleavened Bread, the Feast of Tabernacles, along with the other holy days which the LORD God has commanded that we keep?

Notice ──

“The old Egyptian system, prototype of our present calendar, was composed of twelve 30-day months, each divided into three decades; then at the close of the 360-day year, five feast days were added to complete the 365-day year. The Julian calendar was an adaptation of the Egyptian system, but it took the five extra days and distributed them through the year, and added a new day every four years. Then, in 321 AD, an entirely new feature was introduced into the calendar by Constantine the Great. He commanded the observance of the seven-day week, and appointed the first day of the week ── Sunday ── as the Christian day of worship. (If you consult your own calendar, you will see that Sunday is the first column from the left). This was the first distinctly religious feature ushered into a civil and scientific calendar, and it was not pre-ordained nor written on tablets of stone, but was the whim of a Christian ruler, who exercised his regal arbitrary power, without doing much thinking about what the result would be. …

Our calendar is not Christian in origin. It descends directly from the Egyptians, who originated the 12-month, 365-day system. A pagan Egyptian scientist, {Ancient Greek astronomer} Sosigenes, suggested this plan to the pagan Emperor Julius Caesar, who directed that it go into effect throughout the Roman Empire in 45 BC. As adopted, it indicated its pagan origin by the names of the months──called after Janus, Maia, Juno, etc. The days were not named but were numbered on a complicated system involving Ides, Nones, and Calends. It was not until 321 AD that the seven-day week feature was added when Emperor Constantine adopted Christianity. Oddly enough, for his weekdays, he chose pagan names which are still used.”

(From “Journal of Calendar Reform,” Sept. 1953, along with footnote p. 128 {bracketed ours}).

A hieroglyphic calendar at Elephantine Island on the Nile

Théodule Devéria (French, 1831 - 1871) (1831 - 1871) – photographer

“Hear the word which the LORD speaks to you, O house of Israel. 2) Thus says the LORD: ‘Do not learn the way of the heathen; …’” – Jeremiah 10:1, 2.

Certainly, our Lord Jesus Christ did not use this heathen calendar!

What is God’s living word on what calendar our Lord Jesus used? What calendar did He go by?

The very first time within God’s living word that we come across any evidence of a God-given calendar is found in Genesis 1:14 – “Then God said, ‘Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons, and for days and years; 15) and let them be for lights in the firmament of the heavens to give light on the earth’; and it was so.”

Well, our present-day Gregorian calendar does not meet this qualification. It actually divides the year IN THE DEAD OF WINTER! It divides the day IN THE MIDDLE OF A NIGHT. And its months have no direct link to the moon.

It is not the LOD God’s calendar!

What, then, is the proper method for calculating time by the LORD God’s standard?

A True Unit of Time

In the Book of Genesis, it is revealed to us. Notice ──

“Then God said, ‘Let there be light’; and there was light. 4) And God saw the light, and that it was good; and God divided the light from the darkness. 5) God called the light Day, and the darkness He called Night. …” – Genesis 1:3-4, 5.

And then, six times the term “evening and morning” is used. Always with the evening (darkness) preceding the morning (light) part of each day. So, notice ── as revealed to us by our Creator God ── a day DOES NOT begin in the middle of a night, but it begins at sunset.

This true division of Night and Day was completely understood and followed when our Lord Jesus Christ was on earth. When the Lord’s Sabbath was drawing to a close – notice ── “When the sun was setting, all those who had any that were sick with various diseases brought them to Him; and He laid His hands on every one of them and healed them.” – Luke 4:40.

Even though they fully understood when a day would come to an end, they weren’t aware that our Lord Jesus Christ was more than willing to heal on His Sabbath. Truly, the teachings and traditions of their Jewish rabbis caused them to be ignorant concerning healing on the Sabbath.

So, can the “lights in the firmament of the heavens” “divide the day from the night” ── unless the proper moment of sunset is used to properly divide a day from another day?

A day begins at sunset is also confirmed for us in Leviticus 23. Notice ──

“’ Also the tenth day of this seventh month shall be the Day of Atonement. It shall be a holy convocation for you; … 32) It shall be to you a sabbath of solemn rest, and you shall [humble] your souls; on the ninth day of the month at evening, from evening to evening, you shall celebrate your sabbath.’” – Leviticus 23:27, 32.

Notice that the tenth day begins at the exact moment when the evening begins ── sunset of the ninth day.

Also, the exact moment for a day to end is shown to us in Leviticus 15, in which anyone who is designated as unclean was to bathe in water and be unclean until evening. “’ And when the sun goes down he shall be clean; …’” – Leviticus 22:7. A new day begins at sunset ── not at midnight!

How the Week Came About

Have you ever thought about how the period of time we call the week came about? Was it FIRST revealed to prophet Moses and the children of Israel after their exodus from Egypt? No.

Notice ──

Long before the Exodus, the patriarch Jacob was required to serve his relative Laban for seven years for his younger daughter, Rachel. But, following the first seven years Laban tricked him, bringing Jacob his older daughter Leah, and “he went in to her.” “So it came to pass in the morning, that behold, it was Leah. And he said to Laban, ‘What is this you have done to me? Was it not for Rachel that I served you? Why then have you deceived me?’” And, Laban answered, “’ Fulfill her week, and we will give you this one also for the service which you will serve with me still another seven years.’” – Genesis 29:15-30.

A seven-day period, or a week, followed before he was allowed to have Rachel as his wife, with the stipulation that he had to work for him another seven years.

So, the children of Israel ALREADY KNEW the symbol of “a day for a year” ── truly an important key in properly understanding biblical prophecy. And, they ALREADY KNEW of a seven-day week. This is the first time the word week appears in God’s living word. The Hebrew word being šābûa’, meaning week (a period of seven). In Genesis 1 seven consecutive days are listed for us. The sixth of the seven days mentioned was nearly over when Adam was created.

“Then God saw everything that He had made, and indeed it was very good. So the evening and the morning were the SIXTH DAY.” – Genesis 1:31.

“Thus the heavens and the earth, and all the host of them, were finished.”

Six of the days of creation came to an end, but one thing remained ── a day of rest.

Notice that our Lord Jesus Christ speaks of it ──

“ … ‘The Sabbath was made for man, and not man for the Sabbath.’” – Mark 2:27.

Throughout our history books, it has been recorded the existence of a seven-day week among many ancient nations long before the Exodus. It’s easy to understand why our LORD God commanded us to “’ Remember the Sabbath day, to keep it holy’” because this special day was added to the six-day week the day AFTER Adam and Eve were created. It was made for them, therefore it was made at the time when they were made ── not some twenty-five hundred years later during the Exodus.

The Lord GOD had completed the creation of “the heavens and the earth, and all the host of them” in SIX LITERAL 24-hour DAYS, then, “on the seventh day God ended His work which He had done, and He rested on the seventh day from all His work which He had done. 3) Then God blessed the seventh day and sanctified it, …” – Genesis 2:1-2, 3.

To sanctify means to SET APART FOR HOLY USE.

Friends, this weekly cycle of SIX DAYS of labor, and the SEVENTH DAY the Sabbath of the LORD our God has NEVER been lost by God’s true Church. And this seven day cycle continued down through our Lord Jesus’ time. It was a part of the calendar He kept.

Indeed, we who remember, keep, and observe the SEVENTH DAY OF THE WEEK, called Saturday, are remembering, keeping, and observing the same seventh day that our Creator rested on, blessed, and sanctified!

Now, the existence of our seven-day week demands an explanation. Astronomy does not reason why there is a seven-day week period. A seven-day week period is not divided evenly into 30 days. One source I found states, “The people who gave us the seven-day week were the Babylonians.” 1 Is there any truth to this?

Jeffrey H. Tigay writes  ── a modern biblical scholar who is best known for the study of Deuteronomy and for his contributions to the Deuteronomy volume of the JPS Torah Commentary (1996) ──

“It is clear that among neighboring nations that were in position to have an influence over Israel – and in fact which did influence it in various matters – there is no precise parallel to the Israelite Sabbatical week. This leads to the conclusion that the Sabbatical week, which is as unique to Israel as the Sabbath from which it flows, is an independent Israelite creation.” 2

David M. Henkin, a history professor at the University of California, Berkeley, stated ──

“Some people have argued that there are roots of this in Babylonia [which lasted from around 1900 BCE – 500 BCE] but the evidence for that is pretty slim …” 3

Truly, the only sound and logical origin is found in the literal truth of our Almighty Creator God ── the creation account we see in Genesis 1 and 2. The seven-day week points definitely to a literal SEVEN-DAY PERIOD in which the Lord GOD recreated the earth (cf. Psalm 104:30) and brought forth out of ‘tohu wa-bohu’ all life that had existed upon the earth (and I use the word “had” because mankind has committed specicide on certain animals, along with animals’ own natural selection).

Spring Begins A New Year

So, we see that a new day begins just as the sun sinks below the horizon and that a new week begins with the sunset FOLLOWING THE SEVENTH DAY.

Friends, this was true in Adam’s time, and it is still true nearly 6,000 years later!

Does God’s living word speak to us concerning a new month and a new year? Yes. When were they first made known to mankind?

Our great Eternal Creator God had instructed the children of Israel, while they were still held captive in the land of Egypt, as to when a new year began. Why?

Because this knowledge was lost to the descendants of Israel who had been held in slavery for nearly two centuries. They had lost the LORD God’s method of keeping time. The LORD God had to explain and reveal it. Concerning the first month of a new year, the LORD “spoke to Moses and Aaron in the land of Egypt, saying, 2) ‘This month [the month of Nisan/Abib] shall be your beginning of months; it shall be the FIRST MONTH OF THE YEAR TO YOU.’” – Exodus 12:1-2.

So, the first day of this month ── which occurs at the beginning of spring ── would be the first day of a new year. The FIRST MONTH of our LORD God’s calendar is not January, which is in the dead of winter, but rather in the beginning of spring ── at the beginning of new life. Now, a NEW MONTH and a NEW YEAR begin together ON THE SAME DAY, completely independent of the weekly cycle.

Doing some research for January 1st, it’s interesting to note: How did January 1st become New Year’s Day? We can partly thank the Roman king Numa Pompilius. According to tradition, during his reign (c. 715–673 BC) Numa revised the Roman republican calendar so that January replaced March as the first month. … However, following the fall of Rome in the 5th century AD, many Christian countries altered the calendar so that it was more reflective of their religion, and March 25th and December 25th became common New Year’s Days. 4 Also, January 1st, 1622, the Roman Catholic Church officially adopted January 1st as the beginning of a new year instead of March 25th. 5

“In 1582, the Roman Catholic Church, under Pope Gregory XIII came up with a new calendar, called the Gregorian Calendar. … King Henry VIII of England had thumbed his nose at the pope and declared himself no longer under his control. So his Protestant daughter, now Queen Elizabeth I, wasn’t about to let Rome tell her what day it was. She was having none of this newfangled calendar. So for 170 years, Britain carried on with its old calendar.” 6 The colonies in America naturally followed suit.

The Word Month in the Bible

The word month in God’s living word in Hebrew is ḥōdeš, meaning month, or new moon. The Hebrew word for month when speaking of a calendar is identical to new moon or moon. The appearance of the new moon in our Western sky is just after sunset and is the approximate beginning OF A NEW MONTH! Now, one observer might see first, before all others, a faint slender crescent of a new moon ── should he therefore begin the month earlier than others? Is this man allowed to add a 13th month to the year, while others have to wait until the following year? No. Complete confusion would result.

Mankind is not left to himself to choose a calendar ── and all its constructs. The LORD God is! There is a guiding Authority who determines which months are to have a 30th day and which years have a 13th month. Adding the fact that the LORD God commands us to keep and celebrate the Holy Days, shows us that there is a guiding Authority for us today in this 21st century ── as well. Our Eternal God never fails to provide mankind with knowledge that we must know and can discover.

It was Almighty God who created the entire known universe! He set His heavenly bodies in motion creating a “master-clock” in which true time is determined. Note: Just recently read a great article in which scientists from MIT have developed what they believe is the most accurate atomic clock ever constructed. Be sure to check it out! Recall, that God says, “’ Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons, and for days and years.’” – Genesis 1:14. So the earth’s rotation regulates the length of a day and the lunar phases dictate the length of a month. And the orbit of the earth around the sun – sorry Aristarchus of Samos – dictates the length of a year.

Truly, certain men were given this awesome understanding based upon mathematical principles on which the LORD God’s calendar is based. And, the children of Israel accepted this understanding. The LORD God revealed to these men a calendar that was based upon the laws of mathematics and astronomy. A CALENDAR THAT FOLLOWS THE MOVEMENTS OF THE HEAVENLY BODIES! It is understood that planets can be used as a basis for a calendar, as they have natural time intervals that everyone can agree on.

Is Our Eternal Creator’s Calendar Still Accurate?

Who was it that has preserved God’s calendar down from the time of our Lord Jesus Christ? ── until even today?

Because, if we don’t have an accurate calendar, then in commanding us to keep, observe, and celebrate God’s Sabbath and Holy Days, we are commanded to do something impossible. If the LORD God’s calendar is lost from us, then God’s commandments regarding keeping, observing, and celebrating the Feasts are also impossible. However, since the LORD God DOES COMMAND IT, the calendar is preserved for us!

Who was it that had this awesome responsibility to preserve the calendar? Notice ──

“’ This is he [speaking of Moses] who was in the congregation in the wilderness with the Angel [the angel of the LORD God] who spoke to him on Mount Sinai, and with our fathers, the one who received the living oracles to give to us.” – Acts 7:38.

ORACLES WERE COMMUNICATIONS FROM THE LORD GOD. These oracles were given to all the children of Israel ── to the house of Israel and to the house of Judah. The house of Israel would go into captivity, losing her identity, her knowledge, and her understanding of the LORD God. And, she did not preserve the LORD God’s sacred calendar for us.

Who did?

Well, the house of Judah also went into captivity over 134 years later in 587 BC! Yet, they retained their knowledge of their identity and their God. Even today ── the tiny nation called Israel in the Middle East (truly known as Judah), the Jewish people, have continued in their retention of the knowledge of the Lord’s true Sabbath rest and even of the calendar (which they refuse to accept).

Our Lord Jesus Christ Kept and Followed His Calendar

Let us notice what our beloved apostle Paul asks ──

“What advantage then has the Jew, … 2) Much in every way! Chiefly because to them were committed the oracles of God.” – Romans 3:1, 2.

Friends, the JEWS ALONE were left to preserve for all mankind the LORD God’s living word, the holy Sabbath, along with God’s sacred calendar. Because, if they had not preserved this God-given commission, then our Lord Jesus Christ could not have accurately kept and observed His Passover, the Days of Unleavened Bread, Pentecost, the Feast of Trumpets, the Day of Atonement, the Feast of Tabernacles, and the Last Great Day in their proper seasons during His childhood. He would not have been able to live a sinless life. The LORD God gave the commission of preserving His sacred calendar to the Jews.

Now, our Lord Jesus Christ did indeed accuse the Jews of “’ laying aside the commandment of God [to] hold the tradition of men.’” – Mark 7:8. The commands that our Lord Jesus kept and followed were those written in the Law and the Prophets that Judah was commissioned to preserve. Yet, they themselves refused to believe and or obey.

Our Lord Jesus kept the very same holy Sabbath that the Jews were keeping. He kept the same Holy Days that they were keeping and celebrating ── proving that they (at that time) had a correct understanding of the times of the seasons. (Now, even at that time, certain heretical Jewish sects observed these Holy Days at the wrong times due to their complete misunderstanding of God’s living word). And, in speaking of His living word ── preserved for us with the Law and the Prophets (The Law, also known as the Law of Moses, consists of the first five books of the Old Testament, known as the Torah in Hebrew and the Pentateuch in Greek. The Prophets consists of several books grouped together, Isaiah, Jeremiah, Lamentations, Ezekiel, Daniel, Joel, Amos, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, and Malachi). Our Lord Jesus Christ fully accepted His living word which had been entrusted to the children of Israel by the prophet Moses and the other prophets. He fully accepted and recognized that the Jews had carried out His commission.

Do you!?

Or, are you one of these so-called Christians that is protesting in the streets of the United States of America holding a Palestinian flag while burning a Jewish flag!? Are you ANTI-SEMITIC!?

Do you go to Sunday church every Sunday and read your Bible ── not fully recognizing and understanding that without the Jews preserving for us God’s living word, you wouldn’t be reading God’s living word!? You would possibly be reading some other group's preserved knowledge, or of a sabbath, or “holy” days. NOT THE LORD GOD’S!

So, properly understanding that the LORD God commissioned the Jews to keep His calendar intact ── even up to our day ── we are left with transferring the proper dates from the true calendar of God’s to this present-day Gregorian calendar. (Now I caution you ── do not accept the Jewish dates for the Lord’s Passover or the Day of Pentecost. Because the Jews of today have departed from God’s living instructions regarding when these holy days are to be observed).

If one lacks a reputable Jewish calendar ── to calculate the actual day on which the Feast of Trumpets [called Rosh Hashanah] falls upon in any given year, the expected new moon of Tishri in that year is calculated. This year the Feast of Trumpets is September 23rd. This glorious feast of a memorial of the blowing of trumpets is celebrated on the 1st day of the SEVENTH MONTH. The rest of the Holy Days of the year are quite easily determined from the date of this feast.

The Lord God’s Passover is the first full moon after the March equinox ── April 12th. Note: all these days begin the preceding evening. The Lord’s Passover is to begin Sunday evening just after sunset, which is the 14th day of the FIRST MONTH.

The seven days of the Days of Unleavened Bread are April 13th through April 19th.

The Day of Pentecost (which means, count fifty) is the FIFTIETH DAY AFTER THE WAVE SHEAF OFFERING. This feast will be on June 1st this year.

The Fall Feasts

The next Holy Day ── the Feast of Trumpets. Again, this year the Feast of Trumpets is September 23rd.

Then, on the “’ tenth day of this seventh month shall be the Day of Atonement. It shall be a holy convocation for you; you shall humble your souls, …’” – Leviticus 23:27. The TENTH DAY OF THE SEVENTH MONTH is October 2nd. The day to humble yourself before the LORD God!

Then, “’ the fifteenth day of this seventh month shall be the Feast of Tabernacles for seven days to the LORD.’” – Leviticus 23:34.

The FIFTEENTH DAY OF THE SEVENTH MONTH brings us to October 7th through to October 13th.

The Last Great Day being October 14th.

It is crystal clear that the LORD God has provided all mankind with a holy and sacred calendar that was preserved through the Jewish people. Through them, the LORD God has given us a sacred calendar so that we would be able to keep, observe, and celebrate the holy Sabbaths and the Holy Days as commanded.

The dates for the Holy Days for this year, 2026, and 2027 are available on our website – Holy Day Information & Calendar (Lev. 23, Deut. 16) for your convenience. □

Bibliography:

1) Arndt, G., Why Does a Week Have Seven Days? everything-everywhere.com, 3 Oct. 2022

2) Tigay, Jeffery H. (1998). "Shavua". Mo'adei Yisra'el: Time and Holy Days in the Biblical and Second Commonwealth Periods (Heb.), ed. Jacob S. Licht: 22–23.

3) Baker, N. and Watson, J., Where does the seven-day week come from and why does it govern our lives? Abc.net.au, 4 Jan. 2022. Retrieved 9 Feb. 2025.

4) Tikkanen, Amy. "Why Does the New Year Start on January 1? ". Encyclopedia Britannica, 28 Dec. 2018, https://www.britannica.com/story/why-does-the-new-year-start-on-january-1. Accessed 9 February 2025.

5) Johnson, B., Historic January, Historic-uk.com, Retrieved 9 Feb. 2025.

6) Lestz, M, New Year’s Day, Calendar Years, and the British Tax Year, Margo Lestz – The Curious Rambler, 31 Dec. 2017.