The year numbers are based on the computations of dates and periods found in the Hebrew Bible. In Jewish tradition, "Year 1" is considered to have begun on the 25 of Elul, 6 days before the beginning of "Year 2" on the first of Tishrei, when Adam was created. The new moon of its first month (Tishrei) is designated "molad tohu" (meaning new moon of chaos or nothing). By Halafta's calculation Adam was created during the year 3761 BC. However, "Seder Olam Rabbah" treats the creation of Adam as the beginning of "Year Zero". This results in a two-year discrepancy between the years given in "Seder Olam Rabbah" and the Jewish year used now. For example, "Seder Olam Rabbah" gives the year of the Exodus from Egypt as 2448 AM; but, according to the current system, the year would be 2450 AM.