This excerpt is taken from the book of Fadhilat al-Shaykh Mubashir Ahmad Rabbani, may Allah have mercy on him, Ahkam wa Masail Ramadan.
The Ruling on Preference Between Radio Announcement and the Mu'adhin's Adhan at Iftar Time
Question:.
One day during Ramadan, the announcer announced on the radio that the Maghrib adhan would be in two minutes, but at that very moment, the mu'adhin of the local mosque started the adhan. Which of the two should be followed?
Fatwa:.
If the mu'adhin calls the adhan after observing the sunset and he is trustworthy, then we will follow the mu'adhin because he calls the adhan after witnessing the actual sunset. However, if he calls the adhan merely by looking at the clock without observing the sun, then the prevailing assumption is that the radio announcement is more accurate, as the times on clocks can vary. Therefore, it is better to follow the radio announcement.