The Jewish Day - Jewish Calendar

"And it was evening and it was morning, one day" (Genesis 1:5).

Jewish Calendar Date

When G‑d created time, He first created night and then day. Therefore, a Jewish calendar date begins with the night beforehand. While a day in the secular calendar begins and ends at midnight, a Jewish day goes from nightfall to nightfall. Shabbat begins on Friday night, and a yahrtzeit lamp is kindled the evening before the yahrtzeit (anniversary of a person's passing), before nightfall. If the 10th of Iyar falls on a Wednesday, and a child is born Wednesday night after dark, the child's birthday is the 11th of Iyar.

On those dates wherein certain activities are restricted -- such as working on Shabbat or major holidays -- the restrictions go into effect the night beforehand.

[Most fast days begin at dawn ("alot hashachar"), and as such are an exception to this rule. Yom Kippur and Tisha b'Av, however, do begin at nightfall of the previous night.]

Though the day and its restrictions begin the night beforehand, many obligations associated with specific calendar dates -- such as hearing the shofar on Rosh Hashanah, taking the Four Species on Sukkot, or hearing the daytime reading of the Megillah on Purim -- must be performed during daylight hours only.1

Definition of Nightfall

While a day starts and ends at nightfall, the exact moment when night -- and the next calendar date -- begins is not clear.

The twilight period, from sunset ("shkiah") until three stars are visible in the sky ("tzeit hakochavim"), is an "iffy" time period, known as "bein hashmashot." Shabbat and all the holidays begin at sunset, the earliest possible definition of nightfall, and end when three stars appear in the sky the next evening, the latest definition of nightfall.

A rabbi should be consulted if a boy is born during bein hashmashot (to determine when the circumcision should be scheduled), or if a person passes away during this time (to determine the date when the yahrtzeit should be observed).

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FOOTNOTES
1.	According to biblical law, dawn marks the beginning of the day, and all mitzvot associated with daytime hours can then be performed. For various reasons, however, the Sages instituted that the observance of many of these mitzvot should be delayed until sunrise ("netz hachamah"), or the moment when "one can recognize a familiar acquaintance."

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September 7, 2010

To Beth:

You are correct. The day begins at nightfall. As such, we begin the fast at the evening following the 9th, into the 10th, and then fast for the next 25 hours.

Yes, it would indeed seem that one should perhaps fast for 48 hours, but that is impossible. Thus we eat on the 9th so that we will have strength to fast for the entire duration of the 10th. However, the fact that the Torah did use words that can imply that one should fast on the 9th teach us a number of things. One thing we infer is that we must take in the fast a bit early and actually begin our fast when it is still the 9th. Another thing we infer is that the feasting on the 9th, which helps prepare us for the 10th, is as important as the fasting on the 10th.

The calendar date corresponds to the 18 hours of overlap, not the 6 hours where the Jewish calendar precedes the secular one.

Menachem Posner for Chabad.org

September 6, 2010

Jewish days and calendars

I'm not Jewish but I'm discussing this topic with another Gentile about the Jewish concept of days. We're trying to base our understanding on the Torah but we differ on interpretation.

If eveningg & night is 1 day & feasts are celebrated from evening until the next evening, please explain Yom Kippur -- We know it's Tishrei 10. G-d's people are to fast the evening of the 9th until the next evening which would be the evening of the 10th.

1. Is this the day before the feast?

2. The beginning of a 25hr fast doesn't seem to meet the technicall definition of a evening of the 9th (in Genesis) to the evening of the 10th.

2. Why is the word evening mentioned 3 times in Lev. 23:32?

3. When Jewish calendars are published with Hebrew dates numbered in each block, does the printed day not begin until that evening or does that particular # 'd date really begin the night before? IOW, does the correct calendar date # accompany the 18 hrs of the day or the 6 hrs of previous evening?

Anonymous
Henrico, VA

November 15, 2008

Genesis 1:5 says "it was evening and it was morning, one day".
My question is this; what was before the first evening?
Posted By Stephen L. Dubinsky, Chicago, IL

Eternity....

Dave
Kalkaska, mi

July 15, 2008

RE: time/creation

Before creation there was G-d himself, and His desire to make the world.

Menachem Posner for Chabad.org
chabadandfree.com

July 15, 2008

time/creation

Genesis 1:5 says "it was evening and it was morning, one day".
My question is this; what was before the first evening?

Stephen L. Dubinsky
Chicago, IL
chabadandfree.com