Many people, secular and religious, of different cultures and worldviews have attempted to calculate the age of the world. There is no agreement between them simply because it is an impossible task. Christians, Muslims, and Jews have tried to do the calculation based on a literal reading of the Bible and have come up with different times. The following shows the impossibility by focusing on the widely used Jewish version.
We do not know when some Jews first thought to calculate years from creation. We understand that the talmudic rabbis knew nothing of this calendar, called anno mundi, “year (of the) world,” and used the Greek calendar. Scholars, such as Azariah de’ Rossi, in his The Light of the Eyes, speculate that the anno mundi may have originated around the sixth century, after the Talmudic Period. While this seems to be the date of its origin, it was not until relatively recently that Jews began to use it. Maimonides, for example, dated his documents with the Greek calendar in the thirteenth century. Jews adopted it recently simply because many forgot about its origin and thought it was a divine revelation to the Israelites at Mount Sinai. Other Jews accepted it because it is a “tradition, and one doesn’t question traditions.”
Jewry had good reasons for initially rejecting this calendar. There are theological, practical, and logical reasons why it is clear that the anno mundi is incorrect. The anno mundi inventor calculated the years since creation by taking biblical numbers literally. He relied on imaginative, non-factual, midrashic speculations of dates when the Bible was unclear. He accepted traditions about periods developed to teach homiletical lessons and not historical facts. Scholars feel that biblical time frames and dating were never meant to be taken literally. The Bible is not a history book. It is designed to teach about the existence of God and proper behavior.
The world may have been created over a very long period, humans may not have appeared on earth until millions of years had passed, and the average life span before the flood may not have been hundreds of years, as seems to be indicated by a literal reading of the Bible. When the Torah states that Adam lived for 930 years, it may refer to years that lasted from one lunar cycle to the next, about 29 ½ days. If the 930 “years” are divided by twelve (months), the result is 77.5 currently-calculated years, about the length of lives today. Even if the world was created in a single day, Adam did not die in the year 930 but in 77.
The anno mundi is based on Midrashim. For example, scripture states that Noah bore three sons when he was 500 years old: Shem, Ham, and Yaphet. A midrash states that they were not all born in the same year. According to the Midrash, Shem was not the oldest son, and he was born when his father was 502 years old. The anno mundi is based on Shem’s midrashic birthday, contrary to the biblical text’s plain reading.
Another problem with using the anno mundi is that some of the periods listed in the Bible are questionable. For example, it is possible to date the judges in the book of Judges one after the other, as the book implies, and insist, as does the anno mundi, that the period of the judges lasted over 500 years. However, it is more reasonable to suppose that some judges must have overlapped since they served in different tribes. We cannot determine by how much, and scholars state the period was only about 200 years.
Similarly, when the Bible says that a king ruled for a certain number of years, it is unclear, even as the Talmud recognizes, whether the first and last years are full years of twelve months or parts of a calendar year. In the latter case, two kings would have ruled in the same year and this affects the anno mundi calculation.
Additionally, most post-biblical events are based on questionable traditions. Tradition states that the second temple stood for 420 years, while scholars count the second temple period as over 580 years, from 516 BCE to 70 CE. The anno mundi also assigns dates for people not even hinted at in Scripture; for instance, we have no idea how long King Saul reigned.
In short, some people take the Bible literally and do not accept the basic assumptions used by the anno mundi calculations. Some people take the Bible literally but develop different calculations of the periods mentioned because they interpret the events differently. Many do not accept the literal words in the Torah. Nevertheless, some Jews are convinced that it is a religious duty to use this calendar and feel good when they date their correspondence with the anno mundi year.
 The most famous Christian version, resulting, for example, in the year 2024, was not invented until 525 AD. The initials AD was used in the past and means “The Year of the Lord” (Jesus) in English. BC was used to indicate “Before Christ.” Today, most scholars use CE for “Common Era” and BCE for “Before the Common Era.”
The author of this calendar thought he was calculating since the birth of Jesus. He believed that Jesus was born in the year 1. He made a mistake. A careful reading of the New Testament shows that Jesus was born sometime between 6 and 4 BC.
The author forgot that in the New Testament Gospel, Matthew 2:16, Joseph and Mary were visited by an angel who told them Herod would attempt to kill Jesus, their son. Herod died in 4 BC. So, Jesus was born four or six years before Christ.
 When Rosh Hashana, the New Year, started in September 2023, the Jewish anno mundi year, for example, was 5784 since creation. This widely used calendar dates the patriarch Abraham’s birth to 1948, the same year the State of Israel was reestablished according to the currently-used secular calendar. It dates the giving of the Ten Commandments as 2448, which would be 3336 years before September 2023.
 The same time the Christian calendar was invented.
 It is possible that after the flood, the calculation of years changed, and people considered the difference from a warm to a cold season as a year, so two biblical years during this period are equal to one year today. While the Bible states that Abraham lived 175 years, Isaac 180, Joseph 110, and Moses 120, they would have died at ages 87, 90, 55, and 60, respectively.
 This midrash is not based on anything in the Bible and is contrary to what is stated.
 I Kings 6:1 seems to say the period lasted 360 years from the entry of the Israelites into Canaan until the onset of King Saul’s reign.