(Updated from 3/21/19) Today, June 21, is the summer solstice. But, in the ancient Jewish calendar it was on a different day than the actual solar solstice. Every time I think I have started to grasp the Jewish calendar, that rapidly change. Although rather complex, I will attempt to explain it here. Most years Passover is the first Full-Moon after the vernal equinox. But, sometimes Passover begins on the second Full-Moon after the vernal equinox. This is because the Jewish calendar is lunar based, but the Jewish year solar based. 12 lunar months are shorter than a full solar year. These extra days, that becomes an extra month, are needed to keep the two calendars in sequence. Normally the 1st of Nissan (the 1st month of the Jewish calendar), a New Moon, falls before the vernal equinox, but this year, an intercalary year, it falls on April 6. Alright, that is a little clearer, but wait, the Jewish calendar also has totally different days for their equinoxes called tekufahs. The Jewish Encyclopedia neatly sums this up. It states,
The four teḳufot are: (1) Teḳufat Nisan, the vernal equinox (March 21), when the sun enters Aries; this is the beginning of spring, or "'et hazera'" (seed-time), when day and night are equal; (2) Teḳufat Tammuz, the summer solstice (June 21), when the sun enters Cancer; this is the summer season, or "'et ha-ḳaẓir" (harvest-time), when the day is the longest in the year; (3) Teḳufat Tishri, the autumnal equinox (Sept. 23), when the sun enters Libra, and autumn, or "'et ha-haẓir" (vintage-time), begins, and when the day again equals the night; (4) Teḳufat Ṭebet, the winter solstice (Dec. 22), when the sun enters Capricornus; this is the beginning ofwinter, or "'et ha-ḥoref"(stripping-time), when the night is the longest during the year. Each teḳufah, according to Samuel Yarḥinai, marks the beginning of a period of 91 days and 7½ hours.
To neatly sum this up, the Jewish calendar, based on Moon phases is shorter than the Solar year. Because of this extra days were needed for the Jewish month to occur at the same time of the year. It would be like December occurring earlier and earlier each year. At some point it would occur in the summer. Until next time, GO WITH GOD!
15 years ago I became interested in the date that Jesus was born. This led to several years of research, I quickly realized that there was no valid information that provided any real answers to this question. Since this website is getting some interest, I will post from time to time some of the information I learned during this quest.