272. The Time for Shacharis and Mincha

Tefillah u’Birkas Kohanim 3:1

There is a mitzvah to recite shacharis (the morning service) at sunrise, though the time in which one can say it lasts until the fourth hour, which is one-third of the day. If one intentionally or unintentionally recites shacharis after the fourth hour, he has fulfilled his obligation to pray but not the obligation of prayer in the proper time. Just as there is a positive mitzvah from the Torah to pray, there is a rabbinic obligation to do so it the proper time.

Tefillah u’Birkas Kohanim 3:2

We have already discussed how the time of the afternoon (mincha) prayer service was established corresponding to the daily afternoon sacrifice. Since the afternoon sacrifice was offered at nine and a half hours of the day, the mincha prayer was established at nine and a half hours of the day. This time is known as “mincha ketana” (small mincha). When erev Pesach (the eve of Passover) fell on Friday, the afternoon sacrifice was offered at six and a half hours of the day. It was therefore established that one who davens mincha after six and a half hours has fulfilled his obligation. This time, known as “mincha gedolah” (large mincha) is when the obligation of mincha begins.