What is the ruling on the time limit for the characteristics of fitrah: shaving the pubic hair, cutting the nails, and plucking the armpit hair?

The Shaykh : Here is a question: It says: The question is about the sunnahs of fitrah for which the Messenger of Allah (peace and blessings be upon him) set a time limit of forty days; is this time limit obligatory, such that if we were to leave shaving the pubic hair for a period of forty days, would we commit a sin?
Answer: Yes; because the meaning of setting a time limit is that it is not permissible to exceed it, just as is the case with the times of the prayers. It is not permissible for the one praying to exceed the time of any of the five prayers, and likewise it is not permissible for the pilgrim or the one performing 'Umrah to pass his miqat without entering the state of ihram, from which he is obligated to enter ihram. Similarly, it is not permissible for one who has no valid legal excuse to exceed the forty days for shaving the pubic hair, cutting the nails, or for any of the sunnahs that are among the sunnahs of fitrah. It is necessary to perform these things within the span of forty days, and if this period passes, the one who violates it has committed a sin.