Lailatul Qadr or Laylat al-Qadr

Today is the Islamic holiday Lailatul Qadr or Laylat al-Qadr, which means "Night of Power" or "Night of Decree" (a/k/a Shab-e-Qadr). This is one of the holiest days of the year for Muslims and one of the reasons the month of Ramadan is so important. This holiday commemmorates the revelation of the Quran to the Prophet Mohammad by the Angel Gabriel.

Although Muslims are already fasting, reciting the Quran, giving to charity, praying, etc., during the whole month of Ramadan, because this is such an important holiday, they try even harder during the last 10 days. As I understand it, there is uncertainty and/or disagreement as to which day exactly this falls and it could be any of the odd-numbered days in these last 10.

Extra prayers are said on these days, particularly the night prayer. Those who can afford to devote their time may stay in the mosque for the last 10 days. This worship is called "atekaaf", meaning retreat. Worship on this night is worth more than a thousand months of worship, according to the Quran:

In the name of God, the Benevolent, the Merciful.
1 Lo! We revealed it on the Night of Predestination.
2 Ah, what will convey unto thee 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.

(Qur'an 97, 1-5)

http://en.wikipedia.org/wiki/Laylat_al-Qadr

http://www.geocities.com/mutmainaa/kids/islam/qadr.html

http://www.kingstonmosque.org.uk/LailatulQadr.htm