Laws for Making up for a Missed Prayer - Part 3
One can make up for a missed prayer only during the (next) “time of prayer”, but not when it is not the time of prayer (Shulchan Aruch Orach Chaim 108:3). For example: In a case where someone who missed Shacharit waited awhile after praying his obligatory prayer (such as after Mincha that afternoon), he can no longer make up for the Shacharit prayer that he missed. The reason is because the Rabbis only instituted making up a prayer while one is already involved in praying an obligatory prayer (like Mincha), and since he is praying he can add the “substitute” prayer. But if he is not involved in prayer he cannot pray this additional prayer. (Pri Chadash, Shulchan Aruch HaRav and others)
Many of the later Rabbis disagree with the above ruling, and although they maintain that ideally one should not delay praying the substitute prayer more than the time it takes to walk four amot or say ashrei, however, if one delayed he can still pray as long as the time of that prayer has not passed. Therefore, if one missed Mincha, and during Ma'ariv did not make it up, he can still pray the additional prayer until dawn. (Ma’amar Mordechai, Chayei Adam and others)
The Mishneh Berurah concludes this halacha by quoting the Derech Chaim as follows: Ideally one who did not pray the make-up prayer immediately after his obligatory prayer should pray it as a nedava (voluntary prayer); namely, one should say, “If I am obligated to pray an extra prayer, then this is it, and if I am not obligated to pray a make-up prayer, then this is a voluntary prayer.” Since the Mishneh Berurah did not mention adding something new in the prayer it seems that this is not a requirement. However, the Kaf Hachaim advises to add something new in this prayer since it is easy to do, and one will thereby comply with all opinions in doing so.
Although “after the fact” (bidi'eved), one technically has until the end of the prayer time to make up a missed prayer, the Halacha Berurah by Rabbi David Yosef states that if one began to eat he must stop and pray before continuing.