Prayer: Does Prayer or Iftar Begin at the Start or End of the Adhān?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Does Prayer or Iftar Begin at the Start or End of the Adhān?

English:

Question #359:

Does the time of prayer start as soon as adhān begins to be recited, or is it obligatory to wait till adhān is over? And is it permissible for a fasting person to end his fast as soon as adhān begins or is it obligatory for him to wait until it ends?

Answer #359:

If one is certain that adhān started when the time arrived, it is not necessary to wait until its end.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer