In the short story "The Last Trump" by Isaac Asimov, there is a point where one of the characters explains that the year is calculated differently by various different cultures:
"Nor is that all," Etheriel went on. "The year A.D. 1957 is the year 7464 of the Byzantine era, 5716 by the Jewish calendar. It is 2708 A.U.C., that is, the 2,708th year since the founding of Rome, if we adopt the Roman calendar. It is the year 1375 in the Mohammedan calendar, and the hundred eightieth year of the independence of the United States.
The part that interests me is the Jewish calendar. The year 1957 was not actually 5716 according to the Jewish calendar. The Jewish calendar counts its years from the Jewish New Year (Rosh Hashanah) which occurs around September. Thus, every Jewish year overlaps two regular years, and every regular year overlaps two Jewish years.
For most of the year (January-August) the last digits are identical. When September comes the Jewish year changes, but the regular year does not change until January. Thus, for four months the last digits will be off by one. For example, today it is December of 2018, and the Jewish year is 5779.
If we do the calculations we can see that the year 1957 corresponded to the years 5717 and 5718, while the year 5716 corresponded to the years 1955 and 1956. If you don't trust my calculations, here is a calendar of the year 5716, which shows that the last day of 5716 occurred on September 5, 1956:
And here is a calendar of 5717 which shows that the first day of 5717 was September 6, 1956:
The same calendar of 5717 shows that January 1, 1957 was already well into the year 5717:
So there was no day in 1957 that occurred in the Jewish year 5716.
How can we explain this?
Is it a simple mistake?
Was Asimov following an alternate version of the Jewish calendar that was slightly different?
Is this story meant to be in an alternate reality where the calendars match up slightly differently?
Has anyone ever noted this?
Am I simply missing something here?