When is the time for the 'Aqiqah sacrifice for a newborn?

The Shaykh : A third matter that we must know is the time for the 'Aqiqah. When is the 'Aqiqah performed?
The matter does not come down to the opinion of the guardian or the father, such that he slaughters the 'Aqiqah whenever he wishes. It is not so, for the Prophet (peace and blessings be upon him) said in the aforementioned hadith: Therefore, it is not slaughtered on the second or third day after the birth of the child, but rather on the seventh day. In some hadiths that can be relied upon due to the totality of their chains, it is stated that if it is not feasible for him to slaughter on the seventh day, then it is on the fourteenth day, and if that is not feasible, then on the twenty-first day. So there are three stages with him: the first stage, which is the best, is the seventh day; the second is the fourteenth day; and the third and final one is the twenty-first day. This is a third ruling that we should pay attention to so that we do not miss, first, the performance of the obligatory act, and second, the virtue of the 'Aqiqah, which the Messenger (peace be upon him) referred to in his previously mentioned statement: We said that the 'Aqiqah releases the pledge from the boy or the girl. What is the meaning of the pledge and the release of the pledge here? What has not reached my knowledge is to say that Allah knows best what is intended, but it is undoubtedly a very serious matter. However, some scholars narrated from Imam Ahmad (may Allah have mercy on him), and as you know, he is one of the great Imams of the Sunnah, that he interpreted "releasing the pledge" to mean that it intercedes for his parents on the Day of Resurrection. The intercession of children for their parents on the Day of Resurrection is a matter established in more than one authentic hadith. But Imam Ahmad qualifies those numerous texts regarding the intercession of young children for their parents on the Day of Resurrection by restricting this ruling to the case where the 'Aqiqah has been performed for them. So if the 'Aqiqah is not performed, it means they have no intercession. Since this is a ruling concerning the unseen and requires a scriptural text to hold onto, first, and to convey to the people, second, and since it is a legal ruling and we have not found in the Shari'ah any Book or Sunnah to support the statement of Imam Ahmad, we narrate it but do not make it obligatory to adopt it, because we have not found in the Book or the Sunnah anything to support it. We entrust the true meaning of to Allah (Blessed and Exalted is He). But we believe that it is a very important matter, whether we know the intended meaning as Imam Ahmad explained it, or we do not know it, for "half of knowledge is saying 'I do not know.'" We must submit to the legal ruling with submission, as is the text of the Noble Qur'an. So we must hasten to slaughter for the newborn on the seventh, fourteenth, or twenty-first day. If the Muslim does not do so, it means he has missed the caravan and cannot make up for it. The timing of the 'Aqiqah in this regard is like the 'Udhiyah, whose time the Wise Lawgiver specified by the four days of slaughter: the Day of Sacrifice and the three days of Tashreeq. If the Muslim slaughters his 'Udhiyah on one of the four days of the festival, it is an accepted 'Udhiyah from him in the sight of Allah (Blessed and Exalted is He). If he delays it or hastens it before the festival prayer, it is as he (peace be upon him) said in some hadiths: It is not the meat of an 'Udhiyah for one who has fulfilled his duty toward his Lord (Blessed and Exalted is He). So it is necessary to observe the timing in the 'Aqiqah, just as it is necessary to observe the timing in the 'Udhiyah.