967. Hoshana Rabbah
137:13 If someone became a mourner during Succos, the practice is that he does not go around for Hoshanos. The same is true of one who is in the twelve months of mourning for a parent. He should offer his esrog and lulav to someone who does not have his own so that the other person can go around with them.
138:1 The last day of chol hamoed is Hoshana Rabbah. The practice is to stay up the night before studying Torah as is laid out in the siddur. This is because we are judged regarding water on this holiday, and all human life depends on water. This day is the last day of Succos and everything follows the conclusion. For shacharis, we slightly increase the lights in the shul, as we do on Yom Kippur. The shaliach tzibbur wears a kittel (and our practice is for everyone to wear Shabbos clothes - Mishnah Brurah 664:9). We recite Lamnatzei'ach (Psalm 19) as on yom tov, as well as Mizmor l'Sodah (Psalm 100); we do not say Nishmas. We say Ein Kamocha and Shema when taking out the Torah as we do on Festivals, and Naaritzcha in Kedusha of musaf.