Birkat Halevana: Difference between revisions

* Halichot Shlomo ([[Tefillah]] ch. 15, n. 22) records Rav Shlomo Zalman's minhag to recite [[Kiddush Levana]] after 3 full days even during the months of Tishrei and Av. See Aruch Hashulchan 551:22 and Maaseh Rav 159. </ref>

# One may say Birkat HaLevana until 15 days after the molad, however, on the 16th day one should say it without [[Shem UMalchut]]. Some say that one may only say it until 14¾ days after the molad. <Ref> Shulchan Aruch 426:3 rules like the opinion of Nehardai in Gemara Sanhedrin 41b who say that one has 15 complete days. Chazon Ovadia Chanuka p. 349 agrees unlike the opinion of the Rav Poalim. However, the Rama 426:3 writes that one may only say it up to half of 29 days, 12 hours, and 793 chalakim. Beiur Halacha s.v. VeLo writes that if one is in such a situation where half of 29 days, 12 hours, 793 chalakim passed and 15 days have not, there is what to rely on to say the Bracha. Beiur Halacha adds that if it’s the 16th day one should say it without [[Shem UMalchut]]. Sh”t Yabia Omer 6:38 agrees with the Beiur Halacha that on the 16th day one should say it without [[Shem UMalchut]]. </ref> A chart of the time of the upcoming molads is printed here (see note for calculation)<ref>Rambam ([[Kiddush]] HaChodesh 6:3) writes that from one Molad (the astronomical time when the new moon can be seen) to another is 29 days, 12 hours, and 793 chelakim (and there's 1080 chelakim in an hour). The Rambam 6:8 also writes that the time with which to begin to calculate the Molads from the beginning of creation is the 2nd day, 5 hours, and 204 chelakim. To calculate the Molad of [[Rosh Chodesh]] Tishrei 5773, first let us calculate the number of months which passed from creation and then add the appropriate time for each month. Although there are 12 months in a regular year because there are 7 leap years in a 19 year cycle, there is an average of 12.3684 lunar months a year. By Tishrei 5773, 5772 complete years have passed, meaning that 71390 complete months have passed since creation. The chelakim for the molad of Tishrei 5773 should be 1034 (i.e. 204 + (71390 * 793) modulo 1080) which is equal to 57 minutes and 8 chelakim. Making similar calculations leads to conclude that the Molad for Tishrei 5773 is 1am (i.e. 5+12*71390+(204+71930*793-1034)/1080) mod 24 starting from 6pm) Sunday (i.e. 2+1*71390+(909103-37879)/24 mod 7). The other months can then be calculated from that starting point by either adding or subtracting the interval for each month (1 day, 12 hours, 793 chelakim. To confirm these calculations, one can check the [http://www.chabad.org/library/article_cdo/aid/216238/jewish/Molad-Times.htm Chabad.org page of Molad times].</ref>:  

# The strict halacha allows saying birkat halevana on Shabbat and Yom Tov, but since the kabbalists recommend against it one shouldn't do it unless one is running out of time to say it. <ref>The Rashba (responsa 4:48) quotes someone who said that it is forbidden to say birkat halevana on Friday night since it is like travelling out of the techum above ten tefachim. The Rashba doesn't understand that opinion. He argues that there is no techum above ten tefachim and also it is greeting Hashem and not the moon; therefore, it isn't at all like travelling out of the techum and is permissible to be recited on Shabbat. The Mishna Brurah 426:12 rules that it is permissible to say kiddush levana on Shabbat and Yom Tov if it is necessary. In the Shaar Hatziyun 426:12 he adds a reason that everyone can agree with; since it is a mitzvah filled with happiness a person might come to dance and it is forbidden to dance on Shabbat.</ref>