87. A Minyan

15:1 After Yishtabach, the shaliach tzibbur (prayer leader) says “half Kaddish.” Kaddish, Barchu, Kedusha and reading the Torah require a minyan of ten adult males (see 15:2, below). If a minyan wasn’t assembled when they said Yishtabach but it became completed after, Kaddish is not recited at that point. This is because Kaddish is only said following prayers that were recited with a minyan. Therefore, the advisable practice is to wait for the rest of the minyan to arrive before reciting Yishtabach. (Mishnah Brurah 53:9 says that only the shaliach tzibbur waits to say Yishtabach.) The maximum waiting time is half an hour (during which one may not speak – MB 53:10); after that, they should say Yishtabach, then wait. When the minyan is completed, they may then say some verses (a minimum of three – MB 53:11), followed by “half Kaddish.”

15:2
The definition of “adult” for a minyan is one who has completed his thirteenth year and started his fourteenth. (Halacha requires the start of the growth of pubic hair, which is assumed to be the case.) Some illustrations: one who was born on Rosh Chodesh Nisan becomes an adult on Rosh Chodesh Nisan – that is, after he has completed thirteen full years of life. If one was born in the month of Adar in a regular year (i.e., with one Adar), if his thirteenth year is a leap year (i.e., with two Adars), he becomes an adult in the second Adar. If he was born in the first Adar in a leap year, then he becomes an adult in the first Adar. Those born in either Adar of a leap year will become adults on the corresponding dates of the single Adar in a regular year. This means that someone born early in Adar II will become bar mitzvah before someone born late in Adar I even though he was actually born later. (See Mishnah Brurah 55:45 for the case of one born on Rosh Chodesh Kislev, which can be one day in some years and two days in others.)