- The Night of Qadr: A Night for All of Humanity
According to the sources that we have at hand, it is certain that the Night of Qadr was not exclusive to the time of the Prophet (ṣ) and the region of the Ḥijāz. It is something that will continue forever and in all lands. This is something which is certain and there is no controversy regarding it. The main question here is whether the night begins during a specific and set time and then ends at a set time as well for all those on this earth.
This is a mistaken view because we know that the earth is round in shape and half of it is always in darkness, while the other half is lit by the sun. So it’s not possible for the Night of Qadr to begin at a set time for all the people of the world. The meaning of the Night of Qadr is in reality a night which takes place once a year and this night takes place according to the local time of each area. The people of each area have a certain local time (which is counted according to the lunar calendar for the purposes of the Islamic months) and the month of Ramaḍān begins with the sighting of the moon. Therefore, according to this timeframe, the 19th, 21st, and 23rd nights are the nights which are considered to be the potential Nights of Qadr for the people of that area.
The issue that the people of every locale are to consider their local time in the s e l e c tion of such days is not limited to the Night of Qadr only; it applies to all of the holy days and nights mentioned in Islam. The entire calendar of a specific people is based off of their local time and not the time of any other country or location. This applies to the ‘Īd al-Adḥā, ‘Īd al-Fitr, as well as all other such days. Each of these days is also limited to only one day in a given location (but it can be situated during a different time in another location). It is due to this reason that various days are celebrated earlier in some countries and later in other countries.
This issue also pertains to the ‘coming down of the angels’ during the Night of Qadr. Since night gradually moves across one half of the globe, there is no contradiction if one area celebrates the Night of Qadr during their night and another area celebrates this night during their locally based night. Both times can logically be considered as falling at night.
- Which Night is the Night of Qadr?
There is no question that the Night of Qadr takes place during the month of Ramaḍān; the reason behind this certainty is that the verses of the Quran all express this understanding. For example, one verse states: “The Quran was revealed during the month of Ramaḍān.”  Another verse states: “It was revealed during the night of Qadr.” 
Yet there is some question as to which night during the nights Ramaḍān this took place. Many different dates have been discussed in the books of Quranic commentary. For example, all of the following dates have been listed: the 1st night, the 17th, the 19th, the 21st, the 23rd, the 27th, and the 29th. Yet the most accepted of these dates according to traditions is that this night is situated in the last third of the month and it is either the 21st or the 23rd night.
In some traditions, it is mentioned that the Prophet (ṣ) would confine himself to the mosque during the last ten days and he would busy himself with worship. In another tradition from Imam Ṣādiq (‘a), it has been mentioned that: The night of Qadr is the 21st or 23rd night. At this point, the narrator insisted and asked the Imam (‘a): What if I am unable to worship on both nights; which night should I choose? The Imam (‘a) replied: How easy are these two nights for what you seek.  In many other traditions from the Ahl al-Bayt, the 23rd night has been emphasized. This is while the traditions of the Ahl al-Sunnah have emphasized the 27th night.
In a tradition from Imam Ṣādiq (‘a), it has been narrated that: The designation is on the 19th, the consolidation is on the 21st, and the decree (is signed) on the 23rd.  This tradition is very interesting in that it combines all of the other traditions in to a unified understanding of the issue.  Some people are of the opinion that the night of Qadr has been left unknown amongst the days of the year or the days of the month of Ramaḍān in order that the people spend their time in worship during all of the possible nights. 
 Taken from the text: Pāsukh Be Purseshhāye Madhhabī, Ayatullah Makārim Shīrāzī and Ja’far Subḥānī, Madreseye’ Imām ‘Alī ibn ‘Abī Ṭālib (‘a), Second Print, p. 500.
 Surah Baqarah, verse 185.
 Surah Qadr, verse 1.
 Nūr al-thaqalayn, vol. 5, p. 625, hadith 58.
 «أَلتَّقْدِیْرُ فِى لَیْلَةِ الْقَدْرِ تِسْعَةُ عَشَرَ، وَ الاِبْرامُ فِى لَیْلَةِ اِحْدى وَ عِشْرِیْنَ وَ الاِمْضاءُ فِى لَیْلَةِ ثَلاثُ وَ عِشْرِیْنَ»
 Nūr al-thaqalayn, vol. 5, p. 626, hadith 62.
 Taken from the text: Tafsīr Nemūneh, Ayatullah Makārim Shīrāzī, Dār al-Kutub al-Islāmīyah, 36th Edition, vol. 27, p. 211-213.