All perfect praise be to Allah, The Lord of The Worlds; and may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
The majority of the Muslim scholars, except the Hanafites, are of the view that staying the night in Mina during the days of Tashreeq is an obligatory ritual of Hajj and leaving it entails offering a sacrificial animal and distributing its meat among the poor of the Sacred Precincts of Makkah.
However, the sick who face difficulty in staying the night at Mina are excluded from this ruling and they don`t have to offer a sacrificial animal as expiation.
Al-Imam An-Nawawi (May Allah bless him) said: "The pilgrim, who didn`t stay the night at Mozdalifah or Mina for a valid excuse, doesn`t have to offer a sacrificial animal as expiation." {Al-Majmou`(8/247)}.
If you (questioners) haven`t stayed the night at Mina for a valid excuse, each of you should offer a sacrificial animal as expiation and you can authorize someone to slaughter them on your behalf and distribute their meat among the poor people of the Sacred Precincts. As regards stoning the Jamaraat, it is an obligatory ritual of Hajj and it starts during the three days of Tashreeq after the sun passes the meridian of each day and continues until the sunset of the third day. In other words, there is no harm in stoning the Jamaraat during night time, from sunset till dawn.
However, it is better to stone before sunset as stated in the Hadith narrated on the authority of Ibn Abbas who said: “The Messenger of Allah was asked on the Day of Mina, and he would say: "There is no harm in that, there is no harm in that." A man came to him and said: ‘I shaved my head before I slaughtered (my sacrifice),’ and he said: " There is no harm in that.’ He said: ‘I stoned (the Pillar) after evening came,’ and he said: " There is no harm in that.’ (Bukhari).
Al-Khateeb Ash-Shirbini (May Allah bless him) said: "Stoning the Jamaraat starts from Zawaal time (when the sun passes the meridian) of each day of Tashreeq and ends by the sunset of that day.
However, in terms of permissibility, the stoning time extends from the Zawaal of the first day of Tashreeq until the sunset of the third one." {Moghni Al-Mohtajj(2/276)}.
Therefore, if the stoning was carried out at eleven thirty am of the first Day of Tashreeq, then it is valid, and the same ruling applies to the stoning done at the second day of Tashreeq. However, we would like to point out that authorizing someone to stone the Jamaraat without having a valid excuse is impermissible, except in case of being unable to do so due to an illness. If you have authorized someone to do the stoning on your behalf with no valid excuse, then it doesn`t avail you (doesn`t count) and it is obligatory on each of you to offer a sacrificial animal for leaving this obligatory ritual of Hajj. And Allah knows best.