Question

Asalamualaykum wa rahmatullahi wa barakatuh,

I recently heard from Shaykh Ahmed Saad al-Azhari that astronomical sunset and shari’ sunset are different. Astronomical sunset (which prayer apps and calendars use) is when the middle of the sun dips below the horizon, as opposed to when the entire sun disappears, which is shari’ sunset. Shaykh Ahmed said that the difference between astronomical and shari’ sunset is 2 astronomical degrees, which he approximated to be 8 minutes. Meaning we should wait 8 minutes before breaking fast and praying Maghrib.

This is the first time I’ve heard this, and I wanted to check a second source to see if this is true. I’ve been told to wait 3 minutes before, but waiting 8 minutes seems very long. 

Answer

Waʿalaykum al-Salām wa Raḥmat Allah wa Barakātuh.      

In the name of Allah, The Most Gracious, The Most Merciful.

According to the Royal Observatory in Greenwich, “The published times of sunrise and sunset refer to the moment when the Sun's upper limb, as affected by refraction, is on the true horizon of an observer at sea-level. This occurs when the Sun's centre is 50 arcminutes below the true horizon, the upper limb then being 34 arcminutes (just more than the Sun's apparent diameter) below the true horizon.”[1]

Experience shows that waiting for about two to three (2-3) minutes for the Sun to completely disappear beyond the horizon is sufficient. If you wish to observe extra precaution, you may do so.

And Allah knows best.