Is zakat due on money that reached the zakat threshold last Jumada al-Ula at the then-prevailing gold price, knowing that a year has not yet passed and the current gold price has changed such that the money no longer reaches the zakat threshold at the new price, or is no zakat due on it?

The nisab for money is estimated by the value of the nisab for gold or silver (85 grams of gold, or 595 grams of silver). If the amount reaches the nisab by either of these, and a hawl (lunar year) passes over it, zakat becomes obligatory on it. If it falls short of even the nisab of silver, then there is no zakat on it until it reaches the nisab again and a new hawl passes over it.

There are two opinions regarding considering a decrease during the hawl: 1. Shafi'is and Hanbalis: They stipulate that the nisab must be present throughout the entire hawl, and even a slight decrease breaks the hawl. 2. Hanafis: What matters are the two ends of the hawl. If the nisab is complete at the beginning and end of the hawl, zakat becomes obligatory. A decrease during the hawl does not harm it, as long as the wealth is not entirely depleted. This view is more cautious and more absolving of one's responsibility.