Laylat ul-Qadr, which can be translated as night of power, night of decree or night of measures, marks the anniversary of the night on which the Prophet Muhammad (PBUH) first received revelations from Allah through the Archangel Gabriel, reported Worldbulletin.
A chapter of the Quran deals with this night: "We have indeed revealed this (Message) in the Night of Power: and what will explain to thee what the Night of Power is? The Night of Power is better than a thousand months. Therein come down the angels and the Spirit by God's permission, on every errand. Peace until the rise of morn." (Chapter 97) All Muslims believe that Laylat ul-Qadr is during the last third of the month of Ramadan, but they disagree on which day it is. Sunni Muslims generally believe Laylat ul-Qadr falls on the 21st, 23rd, 25th, 27th or 29th of the month while Shiites believe it falls on the 19th, 21st or 23rd of the month.