# Some say that it's sufficient to add any amount of time before sunset, while others hold that one should add 20 or 30 minutes to [[Shabbat]]. (See footnote for background) <ref>
* How long is Tosefet [[Shabbat]]? Rosh [[Brachot]] 4:6 and Tosafot [[Brachot]] 27a s.v. DeRav agree that one doesn’t have to accept [[Shabbat]] from Plag [[Mincha]] (from ten and three quarter hours). Nonetheless, the Rosh 4:6 writes that certainly there is a minimum time limit but leaves it unclear as to what the limit is. Rabbenu Yonah ([[Brachot]] 18b s.v. Rav) quotes Rabbi Yacov who says that there’s no minimum time and any amount suffices.
* Shulchan Aruch 261:2 and 608:1 rules that there's no minimum requirement of time one needs to add to [[Shabbat]] to fulfill Tosefet [[Shabbat]]. 39 Melachos (vol 1, pg 150) rules like Shulchan Aruch that there's no specific minimum time for
Tofeset [[Shabbat]]. 39 Melachos (Rabbi Ribiat, Hakdama LeMelachat [[Shabbat]], note 667) quotes Rav Henkin who said that in order not to violate [[Shabbat]] and in order to fulfill Tosefet [[Shabbat]] one must add a few minutes before [[Shekiyah]] refraining from Melacha and agrees with this opinion. Eretz Tzvi 70 and Iggerot Moshe 1:96 suggest that one add at least two minutes, Avnei Nezer 4:98 suggests at least four minutes, while Minchat Elazar 1:23 and Teshuvot Maharshag 38 say at least 5. * However, the Mishna Brurah 261:22 quotes the Rosh who argues that a certain amount of time is needed. Beiur Halacha s.v. Ayzo Zman posits that this period of time should be no longer than 3/4 of a [[mil]] (which is 13.5 minutes). The Mishna Brurah 261:23 concludes that in order to fulfill the mitzvah of Tofeset [[Shabbat]] (adding onto [[Shabbat]]) one should refrain from work from the time that the sun is seen at the top of the trees, or to be strict 30 or 20 minutes before [[Shekiyah]]. [Mishna Brurah (Shaar HaTziyun 261:21) explains that by refraining from melacha 20 minutes before sunset one will have satisfied the opinion of the Yerayim to consider the [[mil]] to be 24 minutes and 3/4 of a [[mil]] is 18 minutes.] 39 Melachos (Rabbi Ribiat, vol 1, pg 145) writes that it's not practical to rely upon the method of determining the beginning of [[Shabbat]] by looking at when the sun hits the tree tops but rather one should rely upon times printed on calendars made by halachic experts. </ref># The minhag of yerushalim is to add 45 minutes to [[Shabbat]]. However, women don't need to abide by this minhag. <ref> Shemirat [[Shabbat]] KeHilchata chap 46 note 20. </ref>
==Making early [[Shabbat]] (effects of accepting [[Shabbat]] early)==