Question: Why is it necessary for us to sometimes make such a niyyah (intention) for salat, “I intend to perform the fard of [for example] the first [or the last] Salat az-Zuhr whose time I caught up with but that I could not perform”? Why is it necessary for men to intend likewise when performing zuhr-i akhir on Friday?
Performing a salat does not become fard (obligatory) upon a person as soon as the time for it starts. Performing it becomes fard when the time left before the expiry of its time is so little that it permits only the performance of that salat. It is not fard upon one to perform it as soon as the time for it starts. If the contrary were the case, it would be haram to perform it 10 minutes or half an hour or an hour later. Of course, it is better to offer it immediately when the time for it comes, but offering it becomes fard when it gets very close to the end of its appointed time. For this reason, if one dies without having performed a fardsalat though the time for it has arrived, one will not be accountable for that salat because performing it becomes obligatory when the time left before the expiry of its time is so little that it permits only the performance of that salat. However, when one starts performing a salat after the arrival of its time, it becomes fard to perform it. When one performs it, one has performed the obligatory duty.
Therefore, a man, when performing zuhr-i akhir on Friday, should intend, “I intend to perform the fard of the last Salat az-Zuhr whose time I caught up with but that I did not perform” or “I intend to perform the fard of the last Salat az-Zuhr that was fard upon me but I did not perform.”
If his Salat al-Jumuah is valid, his zuhr-i akhir is counted as the qada (performing a salat after its appointed time) of the last Salat az-Zuhr he missed. If his Salat al-Jumu’ah is not valid, his zuhr-i akhir is counted as the current Salat az-Zuhr. If he intends to perform not the fard of the last Salat az-Zuhr but the fard of the first Salat az-Zuhr, he is counted as having made up the first Salat az-Zuhr he missed, and he is considered not to have performed the current Salat az-Zuhr. It, for this reason, is important whether he intends to perform the first or the last Salat az-Zuhr.
In non-Muslim countries, when one, after performing salat in jama’at, has doubts about the aqeedah of the imam and repeats the salat individually, one should intend, “I intend to perform the fard of the last Salat al-… whose appointed time I caught up with but that I could not perform.” If the imam’s aqeedah is really corrupt, this second salat is considered adaa (performing a salat in its appointed time). If his aqeedah is correct, then his second salat is counted as the last qadasalat of that salat if one missed any.
If you ask why it is better to add [when making the above-mentioned intention], “… I could not perform” instead of “… I did not perform,” the reason is that one’s not performing salat suggests that there is an element of guilt while failing to perform it suggests that one may have an excuse, and it expresses apology. Despite this, there is no harm in saying “… I did not perform.”
During the times when the times of Salat al-Fajr and Salat al-Isha do not start at polar regions, one can intend in the way as explained above. When the time of a salat does not come, one cannot intend, “I intend to perform it in its time.” Instead of it, one should intend, “I intend to perform Salat al-Isha.” Thus, one will have followed those scholars who said that it was fard to perform Salat al-Isha at such regions. If it is not valid according to the other scholars as the time for it does not start, it is better to intend, “I intend to perform the fard of the last Salat al-Isha whose appointed time I caught up with but I could not perform.” If one performs Salat al-Fajr and Salat al-Isha by making such an intention, one will have followed both rulings.