Zuhr & Asr Time

Answer

Istiwaa is the mid way between sunrise and sunset. Zawaal starts immediately after istiwaa. The shadow which appears at the time of istiwaa is called "Fai". Zuhr starts from zawaal and remains until the shade of everything becomes twice the height of any standing object plus the shade at the time of istiwaa. For example, The shade of an object of 25 centimeters is 5 centimeters at the time of istiwaa, so zuhr time will remain until its shade becomes 55 centimeters. Immediately after that asr time will start and it will remain untill sunset. But it is Makrooh (undesirable) to delay asr namaz untill the sun turns yellow. The sun is said to be yellow when one may fix his gaze towards it.