Is it mentioned anywhere in the Holy Qur’an or Sunnah that the Zakah must be paid once a year after calculating certain things. If ‘yes’ please quote the reference. If ‘no,’ please explain how it should be calculated, whether daily, monthly, or yearly basis.
Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
The evidence that Zakah is obligatory every year is the Hadith that the Prophet (Sallallahu Alaihi wa Sallam) said: "No Zakah is due in a property unless one year passes after owning it". [Abu Dawud, Sheikh al-Albani considered it as Saheeh]
All Muslim scholars have agreed upon this matter. The condition of passing a lunar year is considered in livestock, cash, and trade goods. As for plants, fruits, treasures and minerals the Zakah of those materials is given when they are produces.
Allah knows best.
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