What is the maximum limit for completing the recitation of the Holy Qur’an, and are the forty days mentioned in the Hadith the maximum limit for completing the Qur’an only during night prayers (Qiyam al-Layl), or for recitation in general?

The maximum reasonable period for completing the recitation of the Qur'an is forty days. Exceeding this is disliked because it may lead to forgetting the Qur'an and abandoning it. Reciting the Qur'an within this period, whether during prayer or outside of it, is considered fulfilling its right, although recitation during prayer carries a greater reward.