assalamo alaikom, I am considering to pray all my missed prayer from age of maturity. My question are: 1) what is the age of maturity islamically. 2) can i pray all my missed prayer in qyam ul-laiyl? or for qayam-ul-liayl, do i have to pray sepratly meaning other than the missed prayers? Jazakom Allah Khairan

All praise be to Allah, and may His peace and blessings be on the last prophet and messenger, Muhammad,

Let me first congratulate you on your repentance. May Allah accept it.

Secondly, the age of maturity is reached by reaching one of the following 3 milestones:

1- Ejaculation (boys), or menstruation (girls)

Narrated Aisha: “The prophet said, ‘Allah does not accept the prayer of a woman who has reached menarche unless she wears a veil.’”  (Abu Dawood)

2- The growth of pubic hair (pubes)

It was reported that this is how the Companions differentiated between children and adults.

3- Reaching 15 (according to the Mâlikis, Shafi‘is and Ḥanbalis)

Ibn Omar reported that he was not accepted by the Prophet in the army at age 14 and when he reached 15 the Prophet accepted him, Nafi’ said I told Omar ibn Abd al-Azeez of this and he said this is the age of distinction between childhood and adulthood (al-Tirmidhi)

Thirdly, since you will have to make up for so many prayers, you can choose the time that is more convenient for you to do that, including during the night. Certainly, these will be made up prayers, but you will still enjoy standing before Allah (Exalted is He) during that favorable time. You may also pray several dhuhrs with each dhuhr, etc.

“Verily the righteous deeds wipe out those that are evil”

Allah knows best.