Tosfot Shabbat
Related to the previous chapter regarding when one should light the Shabbat candles is the topic of "Tosfot Shabbat" – adding from one's weekday onto Shabbat. The principle of Tosfot Shabbat teaches that one is required to add on to Shabbat by accepting upon oneself Shabbat earlier than the last possible second, which is of course, sunset. Some authorities suggest that adding to Shabbat is actually a mitzva from the Torah.[1] There is no single definitive ruling as to how long before Shabbat one must actually accept Shabbat in order to fulfill the mitzva of Tosfot Shabbat - even 1 minute would suffice for this purpose.[2] There are, however, a number of cited suggestions which include adding: two minutes,[3] four minutes,[4] five minutes,[5] twelve minutes,[6] or fifteen minutes[7]to one's Shabbat observance.
There does not seem to be any clear evidence in halachic literature to suggest that the various customs as to when one should light the Shabbat candles are directly related to the concept of Tosfot Shabbat. Indeed, the previous Zvhil-Mezbuz Rebbe of Boston, Rabbi Jacob I. Korff, encouraged women whose custom it was to light candles at eighteen or twenty minutes before sunset to actually light an additional 2 minutes earlier than this in order for them to satisfy the requirement of Tosfot Shabbat. Similarly, further evidence that candle lighting and Tosfot Shabbat are independent of each other can be seen on Yom Tov where many women have the custom to light the Yom Tov candles well after Yom Tov has begun.[8] Women who have this custom should nevertheless make every effort to fulfill the mitzva of Tosfot Shabbat (which applies on Yom Tov as well) by accepting Yom Tov at one of the recommend earlier times mentioned above even though they will only be lighting the candles later in the evening.
Notwithstanding Rabbi Korff's view, it is interesting to note, however, that whenever a woman lights her Shabbat candles she is concurrently fulfilling the mitzva of Tosfot Shabbat as well.[9] Men can choose their own Tosfot Shabbat practices based on other considerations regardless of when one's wife lights the candles.[10] While one should make every effort to light the Shabbat candles consistently at the same time each week according to one's established family custom, ultimately the mitzva of Shabbat candles is discharged as long as the candles are lit anytime before sunset.
[1] Biur Halacha 261:2
[2] Ritva;Shabbat 9a
[3] Igrot Moshe O.C. 1:96, Eretz Hatzvi 60
[4] Avnei Nezer 4:98
[5] Minchat Elazar 1:23
[6] Siddur Yaavetz
[7] Mishna Berura 261:22
[8] Mateh Ephraim 625:33, Be'er Heitev 503:4
[9] Aruch Hashulchan O.C. 263:13
[10] Mishna Berura 261:63