Is the zakat nisab for money—after the passing of a full year—valued at 80 grams of gold, and is zakat to be paid annually based on the value of 80 grams of gold in the year of its payment?

The nisab (threshold for zakat) for banknotes is estimated based on the value of gold or silver at the time zakat becomes due, and this value fluctuates up and down. The nisab for gold is 85 grams, and for silver, it is 595 grams. Banknotes are valued according to what is more beneficial for the poor. To determine if wealth has reached the nisab, the value of 85 grams of gold or 595 grams of silver is considered. If the wealth equals one of these amounts and a full year has passed, zakat becomes obligatory. The amount of zakat to be paid is one-quarter of one-tenth (2.5%).