Rabbi Yehuda David
Former Rosh Kollel in Dayton
- Introduction – Day and Night in Judaism
- The Source of the Mitzvah of Tosefet Shabbat
- The Duration of the Mitzvah
- Practical Conclusions
In this article we will explore, with God’s help, the source of the mitzvah of Tosefet Shabbat (adding to Shabbat) and how one observes it in practice.
1. Defining day, night, and twilight
For many of us, the words “Let there be light” bring to mind the beginning of the Creation of the world. Indeed, when the Torah describes the first day of Creation, it notes the creation of light and its separation from darkness. At the conclusion of the first day, it says, “And it was evening and it was morning, one day.” This verse is the source of the principle that the twenty-four hour “day” begins at night. This is significant, as it means that Shabbat begins with Friday night.
The period of time between shkiah (sundown) and tzeit hakokhavim (nightfall, when the stars appear) is called bein hashemashot(twilight). There is a dispute as to whether bein hashemashot is considered day or night. The conclusion of the Gemara, therishonim (medieval authorities), and the ShulchanArukhis that because we are uncertain, we must be stringent. This means that on Friday night, bein hashemashot is treated as night (so melakhah is forbidden then); while on Saturday night, bein hashemashot is treated as day (so melakhah is forbidden then as well).
2. Tosefet Shabbat
There is a mitzvah to “add chol to kodesh,” which means we must transform chol (the mundane weekday) into kodesh (the sacred Shabbat) by lengthening Shabbat. This mitzvah is called Tosefet Shabbat. By practicing it, we show that Shabbat is so beloved to us that we want to welcome it early and escort it out late. (This is similar to a guest, whom we go out to greet upon arrival, and whom we escort upon departure.) As we saw above, beinhashemashot is treated stringently, so the mitzvah of Tosefet Shabbat is relevant on Friday night before shkiah, as well as on Saturday night after tzeithakokhavim.
The source for the mitzvah of Tosefet Shabbat is the mitzvah of Tosefet Yom HaKippurim (adding onto Yom Kippur). The Gemara that deals with Tosefet Yom HaKippurim includes three stages:
A) The verse says, “You shall afflict yourselves on the ninth at night.” This would seem to present an internal contradiction. On the one hand, the verse says “the ninth.” This would indicate that the self-affliction should begin on the ninth of Tishrei. On the other hand, it says “at night,” which would indicate that the self-affliction should begin on the tenth of Tishrei. The Gemara resolves the seeming contradiction by explaining that the self-affliction should begin on the ninth, before Yom Kippur actually starts, because we wish to add chol to kodesh. In practice, this means that we begin the restrictions slightly before Yom Kippur.
B) Based on the next words of the verse, “from evening to evening,” the Gemara derives that additional time must be added not only before Yom Kippur, but afterwards as well.
C) The Gemara then extends this requirement of Tosefet to Shabbat and Yom Tov as well.
According to some rishonim and the ShulchanArukh, the mitzvah of Tosefet Shabbat has the status of a Biblical commandment.
3. How much time is required for Tosefet Shabbat?
According to the Rosh, “The exact amount of time is not specified, and it is necessary to stop working a little bit beforebeinhashemashot.” In contrast, the ShulchanArukh rules that one must add “some time” for Tosefet Shabbat.
Among the acharonim (later authorities), there are several opinions as to how much time needs to be added. We shall mention here the two most important ones.
A) The MishnahBerurah rules that in order to fulfill one’s obligation according to all opinions, one should accept Shabbat twenty to thirty minutes before shkiah. The ShemiratShabbatKeHilkhetah comes to a similar conclusion.
B) Rav Ovadiah Yosef is of the opinion that as long as one adds some amount of time, even just a little, one has fulfilled the mitzvah.
It is important to note that according to Ashkenazic custom, there is a link between lighting Shabbat candles and accepting Shabbat. In Ashkenazic practice, women accept Shabbat with the lighting of the candles. If they are careful to light at the time found on the calendars (which is at least twenty minutes before shkiah), they fulfill the mitzvah of Tosefet Shabbat according to all opinions. It is the men who must not forget to accept Shabbat a few minutes before shkiah. In contrast, according to Sephardic custom, women do not automatically accept Shabbat when they light, so they (as well as men) must remember to accept Shabbat at a later time.
On the standard calendars, the time which is listed for Shabbat’s end is fifteen minutes after tzeithakochavim. This way, when it comes to adding time at the end of Shabbat, everybody automatically fulfills the mitzvah.
4. Practical Conclusions
A) Shabbat begins at shkiah. The rishonim disagree about exactly when shkiah begins. Today we are stringent, and consider Shabbat to begin once the sun is no longer visible on the horizon.
B) One who desecrates Shabbat during beinhashemashot is considered an actual Sabbath desecrator.
C) Some rishonim are of the opinion that there is a positive Torah commandment (asei) to add chol to kodesh at both the beginning and end of Shabbat. One who does not do so has neither transgressed a negative commandment (lav) nor is liable to excision (karet). However, one who does do so has fulfilled a positive mitzvah!
D) In order to properly fulfill the mitzvah of Tosefet Shabbat, it is necessary to daven Minchah early enough so that one will finish before shkiah. Otherwise, we are creating a situation in which, by the time Minchah is finished, it is past shkiah, and the mitzvah of Tosefet Shabbat has been lost. For example, candle-lighting time in Tel Aviv is approximately twenty minutes before shkiah. Therefore, it is proper to daven Minchah fifteen minutes before shkiah,to fulfill the mitzvah of Tosefet Shabbat at least according to the more lenient opinions. Of course, davening Minchah in the early afternoon (Minchah Gedolah) could certainly help with this . . . 
E) We conclude Shabbat in accordance with the time marked in the calendars, fifteen minutes after tzeithakochavim, and with that we fullfil the mitzvah of Tosefet Shabbat.
As we say in the zemirot of Shabbat, “May we be privileged to accept Shabbatot with great happiness.”
 This article is dedicated to the refu’ah (healing) of Shachar ben Smadar.  There are many other laws concerning this subject which are beyond the scope of this article. (For additional information, seeShemiratShabbatKeHilkhetah, chapter 40, and YalkutYosef.  Genesis 1:5.  Shabbat 34b.  ShulchanArukh, OrachChaim 261:1.  RoshHaShanah 9a.  Leviticus 23:32  BeitYosef, OrachChaim 261.  ShulchanArukh, OrachChaim 261:2.  The opinion of the Rambam (according to the commentary of the Maggid Mishneh) is that Tosefet Yom Kippur is Biblically mandated, while Tosefet Shabbat is Rabbinically mandated.  Rosh, Yoma, Chapter 8, Paragraph 8.  MishnahBerurah 261:23.  ShemiratShabbatKeHilkhetah, 46:4. In that chapter, the ShemiratShabbat discusses additional issues related to Tosefet Shabbat. These include whether accepting Shabbat early needs to be verbalized or can simply be mentally accepted; whether an individual must accept Shabbat early if his congregation does so; and what someone should do if he comes to shul late on Friday afternoon and does not have time to finish Minchah before the congregation accepts Shabbat.  Responsa Yabi’aOmer, Vol. 5 – OrachChaim #21, Section Bet, s.v. “vehineh.”  See also YalkutYosef, Vol. 4 (Shabbat Part 1), pp. 172-175.  There are a few things which are permitted during beinhashemashot. See ShulchanArukh, OrachChaim 261:1.  MishnahBerurah 261:19.