Liaison office of Grand Ayatullah Sayyid Ali Al Sistani (L.M.H.L) in London, Europe, North and South America.
737. If a stick, a pole, or anything similar to it, which acts as an
indicator (shakhis) is made to stand on a level ground, its shadow will fall
westwards when the sun rises in the morning, and as the sun continues to rise
the shadow cast by the indicator will reduce in size. And in our cities it
becomes smallest at the time of the commencement of Zuhr.
And as Zuhr
passes the shadow cast by the indicator turns eastwards, and as the sun moves
towards west the shadow gets longer. Based on this, when the shadow is the
shortest, and it begins getting longer again, it is known that Zuhr has taken
place. However, in other cities like in Mecca, the shadow disappears totally,
so, when it reappears it indicates Zuhr.
738. The time for Zuhr and Asr prayers is from when the sun starts
declining at midday till sunset. But, if a person intentionally offers Asr
prayers earlier than Zuhr prayers, his prayer is void. However, if a person
had not prayed Zuhr till the end of time, and the time left before Qadha
allows only one Namaz to be prayed, he will first offer Asr prayers in time
and then his Zuhr will be Qadha.
And if before that time a person offers
complete Asr prayers before Zuhr prayers by mistake, his prayer is valid. But
as a recommended precaution, he should treat that Namaz as Zuhr and should
offer 4 more Rak'ats of prayers with the intention of relieving oneself of
responsibility, if any (Ala mafi zzimmah).
739. If a person begins offering Asr prayers forgetfully before Zuhr
prayers and during the prayers he realises that he has committed a mistake, he
should revert his Niyyat to Zuhr prayers i.e. he should intend that from now
onwards till the end of the prayers, it would be Zuhr prayers. After completing
the prayers, he will offer Asr prayers.