Is it permissible for the mu'adhdhin to rely on the Umm al-Qura calendar to determine the time for the adhan?

Question:
He says: Honorable Shaykh, may Allah grant you success, it is reported that it is recommended for the mu'adhdhin to be knowledgeable about the time. Is it sufficient for him to know the Umm al-Qura calendar and rely on it?

Answer:
The Umm al-Qura calendar is accurate and proven, so there is nothing wrong with working by it. However, if he has the capability and knowledge and wants to determine the time himself, that is good. But if he does not have that ability and does not know, then the Umm al-Qura calendar is relied upon. It has been in use for a long time, since the time of King 'Abd al-'Aziz (may Allah have mercy on him). Successive legal committees have reviewed it and approved it, so it is relied upon. Yes.