Daf Yomi - Yoma 87 - Time for Neilah

Rav holds that the tefillah of neilah, the final tefillah prayed on Yom Kippur can be recited at night. Therefore, he rules that if one davened neilah after dark, he will be exempt from davaning maariv that night. His reasoning is neilah is considered an extra tefillah and since one davened a tefillah at night, that will be valid for maariv as well, which is a tefillah that is normally recited at night.

Many rishonim bring down a Gemora found in the Yerushalmi that disagrees with this and therefore they conclude that neilah must be recited by day. The Mordechai writes that although we witness many congregations davaning neilah after dark, this is not because this is the custom, but rather due to a mistake that the chazanim base themselves on.

The Beis Yosef writes that since tefillas neilah is a time that we beseech Hakodosh Boruch Hu for mercy and compassion, it should be commenced earlier in the day to enable the chazan's repeatal of shmone esrei to be by day and at least the birchas kohanim should be before nightfall. He concludes that based on his reasoning, neilah should be started very early in the day which is not practical, therefore the preferable manner is to shorten some of the slichos and pesukim in the middle of the tefillah and to instruct the chazan not to stretch out the words like he usually does.

There is a discussion in the poskim if Rav meant that neilah should be recited after dark preferably or did he mean that it can be recited at that time.