(Qur'an 97, 1-5)

In the name of Allah, the Most Benevolent, the Most Merciful.
1 Lo! We revealed it on the Night of Power.
2 Ah, what will convey to you what the Night of Power is!
3 The Night of Power is better than a thousand months.
4 The angels and the Spirit descend therein, by the permission of their Lord, with all decrees.
5 (The night is) Peace until the rising of the dawn.

The verses above regard the Night as better than one thousand months. The whole month of Ramadan is a period of spiritual training wherein believers devote much of their time to fasting, praying, recitating the Qur'an, remembering Allah, and giving charity. However because of the revealed importance of this night, Muslims strive harder in the last ten days of Ramadan since the Laylat al-Qadr could be one of the odd-numbered days in these last ten (the first, third, fifth, or seventh). Normally, Muslims would perform an i'tikaf in the mosque (i.e they remain in the mosque for the last ten days at a strech) for prayers and recitation.

Laylat al-Qadr, which falls during the last ten days of Ramadhan, commemorates the revelation of the Holy Qur'an and is considered the most holy night of the year. Ramadan ends with the holiday Eid ul-Fitr, on which feasts are held.
Sunnah
Muslims often pray extra prayers on this day, particularly the night prayer. They wake, pray, and hope Allah will give them anything they may desire for on this night. Mostly, they perform tilawat (reading the Qur'an).

Those who can afford to devote their time in the remembrance of Allah stay in the mosque for the final ten days of Ramadan. This worship is called itikaf (retreat). They observe fast during the day and occupy themselves with the remembrance of Allah, performing voluntary prayers and studying the Qur'an, day and night, apart from the obligatory prayers which they perform with the congregation. Food and other necessities of life are provided for them during their stay in the mosque, thus they may not leave the precincts of the mosque except for a genuine religious purpose. Devoting time to remember Allah, Muslims hope to receive divine favors and blessings connected with the blessed night.

Prophet Muhammad peace be upon him was very particular in these regards. It is related that when the last ten days of Ramadan began, he used to keep awake the whole night and was most diligent in worship.

Date
All Muslims believe that the incident occurred during the last third of the month of Ramadan but they differ as to the exact date. Generally consider it to be either the 21st, 23rd, 25th, 27th, or 29th of the month; However, due to the uncertainty of the exact date, Muslims are recommended to observe all the nights as a matter of precaution.