With regard to Tefilat Tashlumin, is one required if one intended to finish his Shacharit Amida before Chatzot but actually finished after Chatzot? (What about if one is m’supak if he finished before or after Chatzot?)

Shalom, One who was praying the the Amidah of Shacharit and started before midday and finished after midday can rely on the Aruch HaShulchan who rules that the time for the Amidah is counted from the beginning of the Amidah and not the end (Aruch HaShulchan O.H. 110,5). This being so, they do not need to pray a tashlumin prayer. If one thought it was before midday and discovered that really it had been after midday when they said the Amidah - if it was in the first half hour after midday they do not need to say tashlumin. Even though it was forbidden to pray Shacharit then, after the fact it counts as Shacharit. (Mishna Brurah, 89, (7)). But after this time, the Amidah was not valid and one needs to pray tashlumin. (see Shulchan Aruch O.H. 89,1, and Biur Halacha "v'achar"). If one is in doubt as to what time it was - from the above we can see that if one isn't sure if they only finished after midday (but certainly started before midday) - or whether it was after midday but certainly less than half an hour after midday, then they do not need to say tashlumin. But if one is in doubt altogether as to whether one prayed in the afternoon or morning, then the law is the same as one who is in doubt as to whether they prayed at all. Because the time for Shacharit has already passed, there is some doubt as to whether one needs to say a tashlumin prayer (see Biur Halacha 108,1 "ta'ah"). One should therefore say a tashlumin prayer with a conditional statement beforehand – "if I am obligated in tashlumin, then this is my tashlumin prayer, and if not, then this is a free will prayer". May all our prayers be accepted (and on time!) Blessings