5778 or 5943?
According to our calendar, we will be ushering in on Rosh Hashana the year 5778.
According to many, there are approximately 165 years missing from the cheshbon and the correct year would be 5943. (less than 60 years to the year 6,000)
My nephew R. Ari Shlita wrote:
"The cheshbon is as follows:
Churban Bayis Rishon happened in 587 BCE - this much is indisputable, as it is corroborated by Babylonian, Egyptian, and Greek inscriptions which match very closely to the accounts in Malochim, Yirmeyahu, and Divrei Hayamim.
Churban Bayis Sheini is commonly taken to be 70 CE by secular historians, but it could be off by a year or two, so may have been 68 or 69. There is a machlokes between Rashi and Tosafos about whether the Bais Hamikdash was destroyed in the 420th year, or after 420 years (Avodah Zarah 9b). This machlokes is based on the fact that it was a motzoei shmittah year. Based on this, the churban should have been 68 or 69. However, we are not so concerned with one year, compared to the bigger problem of 165 years described below.
This puts 656 between Churban Bayis Rishon and Churban Bayis Sheini. The chronologies of these years are very well known, and we know exactly who were the Persian and Greek Kings during these years and how many years each of them reigned, based on multiple corroborating sources. We know exactly when Alexander conquered Israel (329 BCE), and this means there were at least about 400 years from him to the destruction. And the Persian kings from Cyrus to Alexander take up about 200 years. So there are about 600 years - 587 to be somewhat precise, that the Bayis Sheini lasted.
But according to Seder Olam, there should have been 70 + 420 = 490 years between Churban Bayis Rishon and Sheini. This means there are about 166 years missing from our current Jewish date of 5777. Or course, it could be off by a couple of years here or there due to kings starting their reign in the middle of a year, and the year being counted for both, and other such inaccuracies, but 5778 is definitely too low. In general, you need to add about 166 (or 164)."
This subject was addressed by many. It was first addressed by Azariah min Ha'edumim in his Sefer Meor Einayim written in the 1500s. Harav Shimon Schwab zt"l in 1961-2 5722 wrote a lengthy article on this subject. I cut out part of it. The full article can be downloaded (http://www.yutorah.com/ download.cfm?materialID=526681 ).