The Asr prayer is the afternoon daily prayer recited by practising Muslims. It is the third of the five daily prayers (salat). The five daily prayers collectively are one pillar of the Five Pillars of Islam, in Sunni Islam, and one of (the ten) Furoo-ul-deen, according to Shia Islam. The Asr prayer is a 4 rak'ah daily prayer and is prayed (barely1) silently. When travelling, according to some madhhabs, it may be reduced to two rak'ahs. The Asr daily prayer is mentioned by name in the Qur'an at 2:238. And also the name of a short sura (surat al-Asr) in the Qur'an. This raises the Asr daily prayer to a preciously higher rank for practicing Muslims in particular when it falls on Fridays.
However, it is very important to recite the prayer as soon as the time begins. Letter 52 of Nahj al Balagha contains instruction of Ali to his Governors on the timings of Salaat, "The Asr prayers can be performed till the sun is still bright and enough time of the day is left for a person to cover a distance of six miles."
The time period within which the Asr prayer must be recited is the following:
However, it is very important to recite the prayer as soon as the time begins.
1This is for the individual prayer. In the congregation, the recitation will also be unnoticeable except for the expressions which indicate each of the stages of the prayer.
2If the length of an object is 'x' inches. Its shadow's length at noon will be 'y' inches. When the length of the shadow becomes x+y inches, the time for Asr will have set in according to the majority. According to the minority, the shadow must reach 2x+y inches in order for Asr to begin.