How is zakat calculated on an amount deposited in an Islamic bank in installments throughout the year and withdrawn from periodically, and what is the minimum amount in Dirhams on which zakat is obligatory, and to whom is it due?

The Hijri year for money should be calculated starting from the day it reaches the nisab (minimum threshold). Zakat is to be paid after the completion of the year on the existing money, provided it does not fall below the nisab. The amount of zakat is a quarter of a tenth (2.5%), and it is distributed to the recipients of zakat mentioned in Surat at-Tawbah. If "dirham" refers to the silver unit, its nisab is 200 dirhams. However, if other circulating currencies are intended, they must be evaluated in gold or silver, and their nisab is equivalent to 85 grams of gold or more.