My father narrated to us. He said: Sa`d b. `Abdullah narrated to us. He said: Abu Ja`far Ahmad b. Muhammad b. `Isa and Musa b. Ja`far b. Abi Ja`far al-Baghdadi narrated to us from Abi Talib `Abdullah b. Salt al-Qummi from al-Hasan b. `Ali b. Faddal from Dawud b. Abi Yazid. He said: Al-Sadiq Ja`far b. Muhammad said:

When the Sun disappears, then Maghrib time has begun.