Candle Lighting Time
Although there are a number of different customs as to when the Shabbat candles are to be lit Friday afternoons, there is no doubt that the custom for women to light eighteen minutes before Sunset is the most widespread. Regardless of when the candles are actually lit, a woman must formally "accept" Shabbat when she lights them no matter how much time actually remains before sunset and the official arrival of Shabbat.[1] Nevertheless, one is not permitted to light the Shabbat candles or otherwise accept Shabbat earlier than plag hamincha, which is one and a quarter halachic hours before sunset.[2] When one lights the Shabbat candles it should be evident that one is doing so in honor of Shabbat and not for other considerations.[3] In a case of a mitzva or great need, a woman can light the candles without accepting Shabbat if she explicitly declares this intention when lighting.[4]
It is not completely clear where the common custom of lighting approximately eighteen minutes before sunset actually originates from. It is reported that Rabbi Joseph B. Soloveitchik suggested that the custom is based on a practice which was common long ago. The Gemara relates that there used to be a custom of announcing the arrival of Shabbat with a series of six shofar blasts. The last of these six blasts took place "the amount of time it takes to roast a small fish" before Shabbat, after which time Shabbat would begin.[5] This amount of time is said to have been eighteen minutes.
Another view suggests that the custom of lighting eighteen minutes before sunset emerged in deference to an obscure halachic opinion[6] which holds that a Jewish calendar day actually ends eighteen or so[7] minutes before sunset. According to this view, lighting candles, or by extension performing any of the prohibited Shabbat labors, would be forbidden from that time onwards Friday afternoons. Although this view is not accepted as the halacha, it may just be that the eighteen minute custom was initiated in an effort to comply, where possible, with this eminent halachic authority.[8]
There is also an interpretation which teaches that eighteen minutes before sunset was chosen as the candle lighting time in order to recall that shabbat is a "zecher leyitziat mitzrayim", a remembrance of the Exodus from Egypt. As such, the "eighteen minutes" is intended to be reminiscent of matzot which must be baked within eighteen minutes. It is interesting to note that all calendars in the UK as well as the official Boro Park "luach" list the time for Shabbat candle lighting as 15 minutes before sunset. The Satmar Rav also held that Shabbat candles should be lit fifteen minutes before sunset.[9] There is also a legitimate practice to light candles ten minutes before sunset.[10]
Although the predominant custom is to light Shabbat candles eighteen minutes before sundown, there are other customs as well. For example, there is the well known custom in Jerusalem to light Shabbat candles forty minutes before sunset. This custom is derived from a view which requires one to add half of a "halachic hour" to one's Shabbat. This amount of time maximizes to be forty minutes at the height of summer.[11] In order to avoid confusion and ensure consistency, this forty minute period is adhered to all year long even when half a "halachic hour" would be much less than that. In a mirror image of the opinion just cited there is the custom of adding half of a "halachic hour" to Shabbat by lighting candles twenty two minutes before sunset. According to this approach, the twenty two minutes represents the minimum amount of time that half of a "halachic hour" could ever be and is used all year long even when half a halachic hour would really be much more than that.
It is interesting to note that the custom in the city of Petach Tikva is to light Shabbat candles forty minutes before sunset just as is done in Jerusalem. This is because the city of Petach Tikva was founded by Jerusalemites, who when organizing themselves, established that the custom of their former home be adopted in their new one as well. There is a misconception that lighting forty minutes before sunset in other places is to be viewed as a more pious or even meritorious practice, which is simply not the case. Even in Jerusalem there are many communities that officially light the Shabbat candles eighteen to twenty minutes before sunset like most other places in the world.[12] Although certainly a hallowed practice, the "forty minute" custom is ultimately without basis in halacha.[13] Indeed, the "Minhag Yerushalayim" customs are not automatically binding upon anyone who lives in Jerusalem. Rather, they were generally established by and for followers of the Vilna Gaon. There are many communities in Jerusalem who do not observe all of the Minhag Yerushalayim customs.
[1] O.C. 263:4, Mishna Berura 261:25
[2] Shabbat 23b. See Aruch Hashulchan 263:19 who allows accepting Shabbat before Plag Hamincha.
[3] O.C. 263:4
[4] Magen Avraham O.C. 263:20, Tzitz Eliezer 10:19
[5] Shabbat 35b, Minhagei Eretz Yisrael (Gallis) 20:9
[6] Sefer Yereim 274
[7] There are additional approaches on how to understand the Yereim, as well. One view contends that the Yereim holds that the day ends 13 minutes before Sunset, and then 1.5 minutes is to be added for "Tosfot Shabbat" which would put candle lighting time 15 minutes before sunset. There is another understanding to the Yereim which would put candle lighting time at 20 minutes before sunset. See Minhag Yisrael Torah 261:1
[8] Shu"t Mahari Shteif 1
[9] Machzor Divrei Yoel, Zemirot Divrei Yoel
[10] Igrot Moshe O.C. 2:6
[11] Shita Mekubetzet;Beitza 30a
[12] Kaf Hachaim 261:23, Igrot Moshe 2:6
[13] Yabia Omer 5:21