The Hebrew year (shanah) was composed of 12 or 13 months, the latter being the year when an intercalary month was added to make the lunar correspond with the solar year. As the difference between the two was from ten to eleven days, this required the addition of a month once in about three years, or seven in nineteen years. This month was added at the vernal equinox and was called after the month next preceding, we-'adhar, or the "second Adar." We do not know when this arrangement was first adopted, but it was current after the Captivity. There were two years in use, the civil and the ritual, or sacred year. The former began in the autumn, as would appear from
Ex 23:16;
34:22, where it is stated that the "feast of ingathering" should be at the end of the year, and the Sabbatic year began in the 7th month of the calendar or sacred year, which would correspond to
September-October (
Le 25:9). Josephus says (Ant., I, iii, 3) that Moses designated Nican (March-April) as the 1st month of the festivals, i.e. of the sacred year, but preserved the original order of the months for ordinary affairs, evidently referring to the civil year. This usage corresponds to that of the Turkish empire, where the sacred year is lunar and begins at different seasons, but the financial and political year begins in March O.S. The beginning of the year was called ro'sh ha-shanah, and was determined by the priests, as was the beginning of the month. Originally this was done by observation of the moon, but, later, calculation was employed in connection with it, until finally a system based on accurate calculation was adopted, which was not until the 4th century AD. New-Year was regarded as a festival.