124:18 If a baby is to be circumcised on Tisha b’Av, the circumcision should be done after finishing the kinos. The father, the mother, the sandek and the mohel may all wear Shabbos clothes in honor of the mitzvah but they must change out of them after the bris. (They may not wear brand-new clothes – Mishnah Brurah 559:33 – nor may they wear leather shoes – Bi’ur Halacha 559:8 s.v. u’mutar.) Candles may be lit in honor of the mitzvah. The cup of wine used for the brachos is given to a child to drink.
124:19 Tallis and tefillin are put on at mincha with their brachos. (Those who normally wear Rabbeinu Tam tefillin do so also on Tisha b’Av at mincha – Mishnah Brurah 555:4.) We recite the Psalm of the day and the other prayers that were omitted at shacharis. We say Ashrei and half-kaddish, then we read the Torah and the haftarah, the same as on other fast days. We return the Torah to the ark and the shaliach tzibbur says half-kaddish. We say Shemoneh Esrei, adding Nachem in the bracha of “Boneh Yerushalayim.” If one forgot to add Nachem there, he should say it after Aneinu (in Shema Koleinu). He does not conclude this bracha “Menachem Tziyon” (“Comforter of Zion”) but “Shomei’ah Tefillah” (“the One Who hears prayer”). (Mishnah Brurah 557:2 says before “V’sechezena” in the bracha of “R’tzei” and he concludes with “V’sechezena.”) If one did not realize that he forgot to say Nachem until after he said “Baruch Atah Hashem,” he finishes the bracha and continues davening as per usual; in this case, one need not go back.
When the shaliach tzibbur repeats Shemoneh Esrei, he says the birkas kohanim (“priestly blessing”). After Shemoneh Esrei, he says the full kaddish with “Tiskabeil.” The tefillin are then removed, after which we daven maariv. If the moon is shining, we recite kiddush levana. (One should first change into normal leather shoes – Mishnah Brurah 426:11.) See halacha 97:11 that one should eat something before kiddush levana. (If one is going to recite kiddush levana with the maariv minyan before they disperse, then he need not eat first – Shaar HaTziyon 426:9.)