بسم الله الرحمن الرحيم
(Fatwa: 655/J)
According to Hanafi Fiqh, the time of Asr starts from Misl-e-Sani (when the shadow of every object become double after its original shadow) and ends at sunset. For reference and details, please see Ilaus Sunan and Fathul Mulhim.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
