The "Jewish calendar" (or the "Hebrew calendar") used in Israel today is NOT the calendar of God described in the Bible (in the Old Testament, also called "Tanakh" in Hebrew). There are very big differences, which are not known by many Christians and even many Jews. The Israelites themselves have no interest in pointing out the differences, because otherwise they would have to admit that they are acting against God's instruction and miscalculating their feast days. Unfortunately, many Christian churches (Evangelicals, Seventh-day Adventists, the splinter groups of the Church of God...) also equate the Jewish calendar with God's biblical calendar. This is a big mistake, because thus they miscalculate the biblical feast days in many years.

God created the living space and time. He alone has the right to determine the times of assembly (feast days). God's clearly defined astronomical specifications (sun, moon, stars) determine the days, months, years and also all biblical feasts. Human calculations and traditions have no meaning for God, on the contrary, they show rebellion against the Creator. God's Luni-Solar calendar is sensational because it combines the heavenly bodies (sun, moon, stars), nature (phenology), harvest seasons and time into a perfect harmonious unity. However, the Jewish calendar has too many errors and deviates from God's timeline by several weeks in some years because leap years are miscalculated. The following are the most important facts and differences that no one can deny:

• Time of origin and naming: God's calendar and time came into being at the creation of the earth, when the sun, moon and stars (and their respective orbits) were made. God gave us a calendar, not the Jews, because they have their own calendar because they don't want God's calendar anymore. God's calendar existed when there were no people. But the Jewish calendar dates back to the 4th century AD and was completely unknown until then. For the determination of the Jewish holidays calendrical average values are used, which were calculated mathematically. Thus, the Jewish calendar is not only based on the exact astronomical specifications of God (sun, moon, stars), but is mainly based on Jewish calculations and traditions, with additional even pagan (Roman and Catholic) considerations. Therefore it is called "Jewish calendar", but NOT "calendar of God" and NOT "biblical calendar". The calendar of God mentioned in the Bible is not identical with the Jewish calendar and only in a few years the feast days of God fall on the same days in both calendars. Therefore both calendars are also named differently. 
• Origin: The calendar mentioned in the Bible comes from God, but the Jewish calendar is an invention of humans. Attempts are made to approximate God's calendar with mathematical models, but in many years this is not successful. Therefore, the Jewish calendar is not biblical and contradicts the Holy Scriptures. God's calendar described in the Tanakh (Leviticus 23) is based on God's words given to the people of Israel during the Exodus from Egypt through Moses. However, today's Hebrew calendar is not based on the words of God, but on the words and calculations of the Jewish patriarch Hillel II, who worked in the period from 350 to 365 CE. His calendar was invented in 358/359, in the fourth century CE (A.D.), was intended to be permanent, and is still valid in Israel today. Hillel used the Babylonian 19-year cycle with some modifications necessary for Jewish ritual. The beginning of the calendar in the Jewish calendar was taken to be 3761 BCE (B.C.) as the presumed year of creation, which was demonstrably miscalculated because some centuries were missing. Thus the Jewish calendar begins in the wrong year and in the wrong month. It is consequently under several points of view not the calendar which Moses had and it is also not the calendar which was used at the time of Jesus in Israel. 
• Basis and accuracy: God's calendar is based on astronomical facts and is therefore extremely accurate, whereas the Jewish calendar is based only on statistical averages and is inaccurate. The calendar of God described in the Tanakh is a purely astronomical calendar, where each month begins with the first visible crescent moon (the so-called "new light"). This is what God has ordained (not us). However, the current Hebrew calendar is inaccurate, based only on statistical averages, and a month may begin one or more days before or after the first visible crescent moon. Thus, the annual Sabbaths (High Sabbaths, festivals) also fall on the wrong days of the week. Patriarch Hillel II established the beginnings of the month, the duration of the month, and the leap years in the 4th century CE, ending new moon sightings. In the Diaspora (scattering of Jews over the earth), the mathematical Jewish calendar made sense because the first crescent moon could not be seen over Jerusalem. But at the latest after the Second World War, that is, since the return of the Jews to their land, the Jewish calendar no longer makes sense because everyone can see the first crescent moon over Jerusalem. Thus, God's original calendar should have been reinstated, as described in Leviticus 23. God is the one who created the sun, moon and stars, and only He has the right to determine the calendar of time and the setting of feast days. Israel is disobedient on this point as well, preferring to follow its own rabbinic traditions (which many Christians follow) rather than the Creator, God.
• Calendar of a free and an enslaved people: The calendar of God described in the Tanakh is the calendar of a liberated people whom God led out of Egypt. But today's Jewish calendar was invented by a disobedient and therefore captive and enslaved people who were driven out of Israel. Therefore, the people scattered over all the continents of the earth could no longer see the first crescent moon over Jerusalem. The prophetic books often tell how the people of Israel turned away from God, so that God had them punished several times on the 9th of Av (the national day of calamity), when the First and Second Temples were destroyed (the latter in 70 CE). The Israelites were expelled. In the Diaspora, this new calendar made sense because the exiled Israelites could no longer see the first crescent moon over Jerusalem. Thus, the Jews scattered throughout the world could celebrate the holidays together and calculate them in advance. However, when the Jews were allowed to return to their homeland Israel and the State of Israel was "born" on March 14, 1948 (the fig tree began to grow again), the Israelites unfortunately did not adopt God's old calendar described in the Old Testament (Tanakh), but rather their new calendar from the 4th century CE. Thus, the state of Israel today is not based on God's biblical calendar, but on Jewish traditions. 
• Different assembly times: All feast days are meetings (moedim, appointed times) with God, and those who miscalculate these appointed days are celebrating with themselves but not with God. Therefore, the Jews celebrate many feast days not with God but without God, because the true feast days appointed by God are either before or after. In some years there are exceptions (for example, in 2020) when God's calendar and the Jewish calendar fall on the same days.
• Different start of the year: In the book of Leviticus, God designated the month of Abib (Nisan) as the first month, but the Hebrew calendar (see Wikipedia) starts in the seventh month of the religious year, which is the first month of the civil (state) year/calendar. So God's calendar begins in the spring, when life awakens, when the first ears of barley can be harvested and it becomes warmer and lighter. But the Jewish calendar begins in autumn, when the harvest is already over, when the plant life ends and it becomes colder and darker. The connection of the feast days with the harvest times (which also reveal God's plan with mankind) is thus completely lost in the Jewish calendar. The Encyclopædia Britannica describes the calendrical change correctly:
  „In the religious calendar, the commencement of the month was determined by the observation of the crescent New Moon, and the date of the Passover was tied in with the ripening of barley. The actual witnessing of the New Moon and observing of the stand of crops in Judaea were required for the functioning of the religious calendar. The Jews of the Diaspora, or Dispersion, who generally used the civil calendar of their respective countries, were informed by messengers from Palestine about the coming festivals. This practice is already attested for 143 BCE. After the destruction of the Temple in 70 CE, rabbinic leaders took over from the priests the fixing of the religious calendar. Visual observation of the New Moon was supplemented and toward 200 CE, in fact, supplanted by secret astronomical calculation. But the people of the Diaspora were often reluctant to wait for the arbitrary decision of the calendar makers in the Holy Land. Thus, in Syrian Antioch in 328–342, the Passover was always celebrated in (Julian) March, the month of the spring equinox, without regard to the Palestinian rules and rulings. To preserve the unity of Israel, the patriarch Hillel II, in 358/359, published the “secret” of calendar making, which essentially consisted of the use of the Babylonian 19-year cycle with some modifications required by the Jewish ritual.“
• Different number of days in a month: God's calendar does not have a uniformly fixed number of days. Each month can have either 29 or 30 days according to astronomical specifications. But the Jewish calendar has a predetermined number of days in each month set by humans (see Wikipedia). Thus, the length of the month is not calculated according to God's astronomical clock, but according to Jewish tradition, which is based in part on calculations from the time in Babylon. In the biblical calendar, the months are usually numbered rather than named. Only the first month, Abib (Aviv; Ex 34:18), had a name meaning "barley ripening" (ripening of ears). In post-exilic literature (cf. Neh. 2:1) the month is called by its Babylonian name, "Nisan." The Jewish calendar adopted the Babylonian names of the month, which are still used in Israel today. They indirectly indicate that the people of Israel were expelled from their land because of their disobedience, where they adopted the Aramaic language and also some pagan calendar traditions.  
• Different determination of leap years: In God's calendar, the ripeness of the early grain determines when the first month of the year begins. But in the Jewish calendar, leap years are determined mathematically (see Wikipedia). As a result, in some years, harvesting the early grain (see Omer) at Passover would be problematic or impossible. See the chapter on harvest seasons in Israel. In the Jewish calendar, leap years are determined mathematically (without regard to astronomy) and occur only seven times in a 19-year cycle (in the 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years). Thus the connection to the equinox is often lost, which is a big mistake. In God's calendar, the spring and fall feasts are always near the equinox (March 19-21 & Sept 22-24), but in the Jewish calendar often a month after, thus too late. As the Jewish calendar inserts an additional 13th leap month at the wrong time in 2024, the biblical calendar and the Jewish calendar are a whole month apart in 2024. This means that the Jews and also some Christian groups celebrate all 7 feast days at the wrong time and do not gather with the God of the Bible, but with themselves or with another god. The Jewish feasts in 2024 are a whole month after the equinox, which is absolutely impossible in the biblical calendar of God.
• Different offerings of the First Fruits: The years 2023 and 2024 in particular show how important a correct calculation is, because there is a whole month between the astronomical biblical calendar and the imprecise mathematical Jewish calendar, so that the day of the firstfruits of barley (16th of Nisan) is also extremely different (March 27 or April 24, 2024). At the end of April/beginning of May 2024, there will be almost no barley left in the fields of Israel (except in the highlands), as the barley grains fall to the ground quickly and have to be harvested beforehand. Some photos of the harvest times in Israel in 2024 prove that the Jewish calendar completely miscalculates the leap month and the Omer in 2024. God has commanded that the harvest of early grain may only begin after the sheaf of firstfruits is waved in the temple on the 16th of Nisan, but in 2024 farmers must harvest earlier. If they had to wait until April 24, they would lose part of the harvest. In 2020 and 2023, both calendars were identical for Passover. 
• Different determination of the feast days: The Jewish calendar was built up in such a way that certain annual Sabbaths (High Sabbaths, feasts) cannot fall on certain weekdays. The biblical calendar of God does not know these human regulations, but the month beginning is aligned alone with the first visible crescent moon (the new light). Thus, the biblical feast days are clearly determined and can fall on different weekdays from year to year, without certain restrictions that can move the beginning of the month forward or backward. 
• Complicated instead of simple: The calendar of God is very simple to understand and logically developed. Every person can see without computer by the illumination of the moon when a month (and therefore also a year) begins and in which day of the month it is. But the Jewish calendar has lost the connection with nature. The Jewish calendar is very complicated and illogical and when a person sees the first crescent moon and the full moon at night, he can only hope that it is the beginning of the month (or year) and the middle of the month, because the Jewish calendar is often off by one or more days, sometimes even a month. Thus also the feasts of God are on the wrong days and there is an uncertainty whether the right days are kept according to God's will. In the calendar of God this uncertainty never exists.
• It is not just a matter of obedience or disobedience, but of life and death: Only once a year (on the High Sabbath of Yom Kippur) was the high priest allowed to enter the Holy of Holies in the temple. If he entered on a wrong day, which did not correspond to God's calendar, he had to die. For this reason, the high priest often had a sheath tied around his body so that he could be pulled out if he died, because no other person was allowed to enter this area. If the priest followed the Jewish calendar invented by man (Hillel II) and currently still used in Israel, he would have died upon entering the Holy of Holies in the Temple. So the difference between these two calendars has not only to do with different teachings and opinions, but it is even a matter of life and death. If there is to be a temple in Jerusalem again, then this must be carefully considered. If there were still a temple in Israel today, the priest would have to die in many years when he enters the Holy of Holies in the temple. The Jewish Yom Kippur (Day of Atonement) would therefore often be a funeral day. So it would be in 2021, when the Day of Atonement (Yom Kippur) was celebrated 2 days early in Israel. In 2020, the priest would not die because the biblical and Jewish calendars fell on the same days. 
• Calendar differences of several days/weeks: The calendar described in the Old Testament (OT, or Tanakh) is clearly defined on the basis of astronomical facts; but the current Jewish (Hebrew) calendar is an invention of people who try to approximate God's calendar but do not want to adopt it. In some months the two calendars are identical, as in 2020, when Passover and therefore Pentecost (Shavuot) fell on exactly the same feast days in both calendars. But in many years there are differences of one or even several days, in extreme cases even by several weeks, if the leap years are calculated incorrectly. In 2021 there were differences of 1-2 days between the two calendars, in some years both calendars are almost identical (e.g. 2020, 2023) and in other years (e.g. 2024) there is a whole month in between, examples:

The Jewish mathematical calendar of Israel 2021 according to Hillel (e.g.  Chabad,  Hebcal,  Aish,  HaGalil):
     Passover (Nisan 15): March 27/28, 2021 (15th day of the 7th month).
     Shavuot: May 16/17, 2021 (the 50th day after Passover).
     Tisha B'Av: July 17/18, 2021 (9th day of the 11th month)
     Tu B'Av: 23/24 July 2021 (15th day of the 11th month)
     Yom Teruah: September 6/7, 2021 (1st day of the 1st month)
     Yom Kippur: September 15/16, 2021 (10th day of the 1st month)
     Sukkot: September 20-27, 2021 (15th-21st day of the 1st month)
     Shemini Atzeret: September 28, 2021 (22nd day of the 1st month).

God's Biblical Astronomical Calendar 2021 (e.g. TorahCalendar):
     Passover (Nisan 15): March 28/29, 2021 (15th day of the 1st month).
     Shavuot: May 17/18, 2021 (the 50th day after Passover)
     Tisha B'Av: July 19/20, 2021 (9th day of the 5th month)
     Tu B'Av: 25/26 July 2021 (15th day of the 5th month)
     Yom Teruach: September 8/9, 2021 (1st day of the 7th month)
     Yom Kippur: September 17/18, 2021 (10th day of the 7th month)
     Sukkot: Sept. 22-29, 2021 (15th-21st day of the 7th month)
     Shemini Atzeret: Sept. 30, 2021 (22nd day of the 7th month)

In 2023, the first 3 biblical feast days in spring/summer fall on the same feast days in both calendars (see 2023). First the Jewish feasts of Israel are mentioned (red), the bold marked data correspond to the calendar of God. They are correct and independently confirmed by Christians worldwide (e.g. TorahCalendar.com):

Between the 7 biblical feast days in 2024 (High Sabbaths, annual Sabbaths) according to the biblical calendar of God (marked in bold) and according to the imprecise Jewish calendar of Israel (marked in red), there is even a whole month in between in 2024:

1.) Passover 1 (Nisan 15):  Mon/Tue, March 25/26, 2024 - Mon/Tue, April 22/23, 2024 [5784]

• Correct determination of the biblical feast days: Today we have astronomical data (e.g. from NASA) with which the first crescent moon (the New Light), which can be seen over Jerusalem in most months, can be determined with certainty. Thus, all dates of the biblical calendar can be calculated in advance (dated) or backdated by several millennia. However, it must be noted that the leap months (about every three years) must be calculated correctly, because this is where most errors occur. 
• Determination of the 1st month of the year: Some theologians and pastors make the mistake to begin the first month of the year always with the first visible crescent moon after the equinox. This is wrong, because the decisive criterion was always the condition of the early grain (barley), which had to be in the ripe stage "abib" (see barley wheat harvest Israel). On the day after the High Sabbath (15th of Abib/Nisan, Passover), i.e., on the 16th of Abib/Nisan, the sheaf of firstfruits was offered in the Temple, and only then was the barley harvest allowed to begin (see Omer). But if we had started the first month a month later, the barley grains would have fallen on the ground, which would have had a terrible symbolic meaning. Therefore, the farmers and the priests always went to the fields before the beginning of the month to check if the barley was ripe enough to be harvested in the middle of the month (on the 16th of Abib; see Omer). If the barley was not yet ripe, a leap month was inserted. Thus, there was always harmony between God's calendar and harvest times. All God's festivals are also harvest festivals in the three harvest seasons: in spring (Passover: barley), in summer (Shavuot: wheat), in autumn (Yom Teruah/Kippur, Sukkot: grapes and fruits, later olives).
• 3-Dimensional Calendar: The specific star constellations in the night sky in the respective months indicate apart from the season also the exact geographical position; thus each humans can orient themselves on earth on the basis of sun, moon and stars exactly in time and space. God's calendar is thus an astronomical, agricultural, and geographical calendar (3-dimensional) that combines nature and time into a perfect harmonious unity. No other calendar in the world offers this accuracy, so only this calendar will last forever. But the Jewish calendar is inaccurate and in some years deviates from God's calendar not only by a few days, but even by a whole month, because the leap years are calculated incorrectly and the state of nature is not taken into account. This is a huge mistake. The Jewish calendar is not three-dimensional, because it does not pay attention to the first visible crescent moon over Jerusalem, nor to the state of nature (ripeness of the barley), nor to the constellations of stars. It is based only on the mathematical rules of the Jews, who were expelled worldwide by the Romans from 70 AD. Therefore it is called "Jewish calendar" but NOT "calendar of God" and NOT "biblical calendar".
• Future and eternity: When God re-establishes His kingdom on this earth, there will again be the calendar of God described in the Tanakh worldwide and never again the present Hebrew calendar. The Jewish calendar will be abolished, but God's calendar will be introduced worldwide. Then, of course, the Gregorian (Catholic) calendar will also no longer exist. God's calendar is ingenious, because only this calendar connects the heavenly bodies (sun, moon, stars), nature (phenology, development status of the plants, harvests), the geographical location and time to a harmonious unity. 

If someone has a different opinion and equates both calendars, he is invited to show us the possible errors in the above points on the basis of the OT (Tanakh). So far, no one has succeeded in doing so, and we also have good contacts in Israel who confirm the above and the differences. The following list shows the different feast dates in the two calendars and clearly shows that in many years a high priest in Israel would die if he entered the Holy of Holies in the Jerusalem Temple on the wrong day:

The example of the foundation of the state of Israel shows how important it is to differentiate between the Jewish and the biblical calendar, because otherwise important prophetically predicted events cannot be correctly classified in their symbolism. In the first mentioned calendar often the leap years and therefore also the feast days are calculated wrongly. The day of the birth of Israel on Friday, May 14, 1948 was in the Jewish calendar only the 5th Iyar (5th day of the 2nd month); but in the biblical calendar of God it was the 4th Sivan (4th day of the 3rd month), thus directly the day before the 7th Sabbath in the Omer-counting and even directly before the Pentecost (beginning from sunset on May 15, 1948; see TorahCalendar). This is symbolically of great significance, for thus the birth/founding of Israel (prophetically: the unfaithful bride) occurred at the time of Pentecost, just as the birth/founding of the New Testament Church (prophetically: the bride of Christ) occurred at Pentecost (Acts 2). So there was a great Pentecostal miracle not only in the year of Jesus' resurrection, but also in May 1948, the year of Israel's rebirth. Due to the fact that the Jews reject the calendar of God, although it was the original calendar of their fathers, this important basic knowledge remains hidden from them and many are not aware of the participation of God in the foundation of the state, so that they do not thank Him. They do not know that the oft-quoted newspaper "The Palestine Post" (pictured) proclaimed the birth of Israel to the entire world exactly on May 16, 1948, and that day was Pentecost! So the official and worldwide proclamation of the foundation of the state of Israel (The Independence Day) took place on a Pentecost day, on Sunday, May 16, 1948. This also means: The beginning of the fig tree generation was officially announced on a Pentecost day to all Christians who are waiting for the coming of their Lord (see Rapture). Thus they have a clue how to reckon. 

In Jewish circles, there is a strong interest in hiding God's calendar from the world. Why? Because the opinion is spread that the Jewish calendar is allegedly biblical and should correspond to the will of God. This is completely false, as has already been proven above in the text. Many Christian churches have fallen into this trap, such as the Adventists and the Evangelicals. Even the Church of God does not align its feast days according to what the Bible says, but according to the Jewish calendar with its own rabbinic traditions. Thus, they usually celebrate their "biblical feast days" at the wrong time and thus gather not with God but with themselves. The fact is: The Jewish calendar is not the calendar of God mentioned in the Bible (Tanakh), but is the calendar of Jews who have made up their own traditions, which they follow until today. The calendar of the Bible was and is also the calendar of Jesus Christ and this is also the only calendar which will have eternal existence. The Jewish calendar, on the other hand, which is partly based on Babylonian specifications, has no future. It will never succeed to hide the calendar of God from the world, because it is mentioned in the Bible and therefore everybody can get to know it, even if some Jews and Christians want to hide it or replace it.

Jesus (a descendant of David) repeatedly criticized the Jews for putting their own rules and traditions before the Word of God:

Mk 7:6-9: „And he said to them, “Well did Isaiah prophesy of you hypocrites, as it is written, “‘This people honors me with their lips, but their heart is far from me; 7 in vain do they worship me, teaching as doctrines the commandments of men.’ 8 You leave the commandment of God and hold to the tradition of men.” 9 And he said to them, “You have a fine way of rejecting the commandment of God in order to establish your tradition!“

After the Rapture, the Jews will have to go through the 7-year tribulation. They will then look to Jesus and His love, whom they have rejected until then. He came to His people, but His own relatives did not recognize Him and rejected Him: 

Jn 1:1-11: „In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was in the beginning with God. 3 All things were made through him, and without him was not any thing made that was made. 4 In him was life, and the life was the light of men. 5 The light shines in the darkness, and the darkness has not overcome it.. 9 The true light, which gives light to everyone, was coming into the world. 10 He was in the world, and the world was made through him, yet the world did not know him. 11 He came to his own, and his own people did not receive him. 12 But to all who did receive him [the Christians from the Gentile nations], who believed in his name, he gave the right to become children of God, 13 who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.“ 

Isaiah 7:14 and chapter 53, Psalm 22 clearly testify about Jesus. Isaiah 53 is the "forbidden chapter", which must not be read in the synagogue, because it creates too much unrest, because it reports prophetically about Jesus. Every Jew in Israel and all over the world should know this:

Acts 4:10-12: „let it be known to all of you and to all the people of Israel that by the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead - by him this man is standing before you well. 11 This Jesus is the stone that was rejected by you, the builders, which has become the cornerstone. 12 And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved.“

The biblical calendar of God, which is defined in Leviticus 23, is a purely astronomical luni-solar calendar. This means that the sun, moon and stars are not only lights, but also determine the calendar and the feast days. The calendar of God is ingenious because it combines nature and time into a harmonious unity. It is defined by 7 points:

1. Each day begins and ends after sunset. Thus, the sunrise in the morning is in the middle of a whole calendar day and and ends at the beginning of darkness.

2. A week consists of 7 days and the 7th day is called "Sabbath" (ceasing, resting).

3. Each month begins with the first visible crescent moon over Jerusalem, which is called "new light". In the middle of each month there is a full moon. In addition to the weekly Sabbaths, there are also 7 annual Sabbaths ("High Sabbaths") that fall on different days of the week from year to year, depending on which day of the week the first crescent moon can be seen first in the 1st and 7th months. 

4. Each month has 29 or 30 days.

5. A year normally has 12 months. However, since the lunar year is about 10,87 days shorter than the solar year, there is a leap year about every third year with an additional month to bring the calendar in line with nature (phenology). Thus, the spring festival of Passover (Nisan 15) and the autumn festival of Sukkot (Tishrei 15) always fall near the equinox. Since Passover is a spring festival, it may not be celebrated in winter; therefore, the first high Sabbath of the year (Nisan 15) is always either on (e.g., 2011) or usually after the day of the spring equinox but never before. The leap year also prevents the feast days from moving throughout the year, as is the case with the lunar calendar. The leap year also prevents the feast days from wandering throughout the year, as is the case with the lunar calendar.  

6. The first month of the year is determined by observing nature, especially the ripeness of the early grain (barley), more precisely according to the state of maturity called "abib" (fresh young barley ears, Strong No. 24), which occurs only once a year. At the end of the year, when the farmers and priests saw that the barley was still too unripe to be cut in the middle of the month, an extra month was added by the high priest. This way, the first month of the year could always be defined without dispute, and the first ears of barley (first-fruits sheaf, Omer) could always be presented as a wave offering in the temple at Passover. Thus, all 7 feast days were always within the range of the harvest seasons in Israel, which also indicates their symbolic spiritual significance in God's plan with humankind. See Barley and Wheat Harvest in Israel.

7. The specific star constellations in the night sky in the respective months indicate apart from the season also the exact geographical position; thus each humans can orient themselves on earth on the basis of sun, moon and stars exactly in time and space. God's calendar is thus an astronomical, agricultural, and geographical calendar (3-dimensional) that combines nature and time into a perfect harmonious unity. No other calendar in the world offers this accuracy, so only this calendar will last forever. 

The calendar of the Bible (God's calendar) and the seven feast days of God show a connection with the harvest seasons and God's plan for humankind:

Spring (feast of spring fruits: barley): 

1)     1st month Nisan, 15th day: Passover 1, 1st day of unleavened bread  (Pesach 1)

2)     1st month Nisan, 21st day: Passover 7, 7th day of unleavened bread  (Pesach 7)

Summer (feast of summer fruits: wheat):

3)     The 50th day after the first High Sabbath: Pentecost  (Shavuot, Feast of Weeks) 

Autumn (feast of late fruits: grapes and fruits):

4)     7th month Tishrei,   1st day: Day of Trumpets  (Yom Teruah) 

5)     7th month Tishrei, 10th day: Day of Atonement  (Yom Kippur)

6)     7th month Tishrei, 15th day: Feast of Tabernacles  (Sukkot, 15th-21st day)

7)     7th month Tishrei, 22nd day: Last Great Day of Assembly (Shemini Atzeret, 8th day of assembly, conclusion)

In 2020, the Jewish calendar fell on the same feast days as God's biblical calendar. But in many years the Jews and also some Christian groups celebrate the wrong feast days because they do not follow the Bible but the human traditions of ancient rabbis. 

Isaiah 53:1-12: Who has believed what he has heard from us? And to whom has the arm of the Lord been revealed?

2 For he grew up before him like a young plant, and like a root out of dry ground; he had no form or majesty that we should look at him, and no beauty that we should desire him.

3 He was despised and rejected by men, a man of sorrows and acquainted with grief; and as one from whom men hide their faces he was despised, and we esteemed him not.

4 Surely he has borne our griefs and carried our sorrows; yet we esteemed him stricken, smitten by God, and afflicted.

5 But he was pierced for our transgressions; he was crushed for our iniquities; upon him was the chastisement that brought us peace, and with his wounds we are healed.

6 All we like sheep have gone astray; we have turned - every one - to his own way; and the Lord has laid on him the iniquity of us all.

7 He was oppressed, and he was afflicted, yet he opened not his mouth; like a lamb that is led to the slaughter, and like a sheep that before its shearers is silent, so he opened not his mouth.

8 By oppression and judgment he was taken away; and as for his generation, who considered that he was cut off out of the land of the living, stricken for the transgression of my people?

9 And they made his grave with the wicked and with a rich man in his death, although he had done no violence, and there was no deceit in his mouth.

10 Yet it was the will of the Lord to crush him; he has put him to grief; when his soul makes an offering for guilt, he shall see his offspring; he shall prolong his days; the will of the Lord shall prosper in his hand.

11 Out of the anguish of his soul he shall see and be satisfied; by his knowledge shall the righteous one, my servant, make many to be accounted righteous, and he shall bear their iniquities.

12 Therefore I will divide him a portion with the many, and he shall divide the spoil with the strong, because he poured out his soul to death and was numbered with the transgressors; yet he bore the sin of many, and makes intercession for the transgressors.

"But you, Daniel, shut up the words and seal the book, until the time of the end.

Many shall run to and fro, and knowledge shall increase."

(Daniel 12:4)

 "Prove all things; hold fast that which is good. Abstain from all appearance of evil"

(1Thessalonians 5:21-22)

"Take no part in the unfruitful works of darkness, but instead expose them"

(Epheser 5:11)