How is zakat calculated on money deposited in an Islamic bank in installments? Is it a condition for a full year to pass on each installment, or on the total amount? Are profits added to the principal when calculating zakat? And how is zakat calculated on funds deposited in Saudi Riyals and US Dollars?

Zakat becomes obligatory on wealth when it reaches the nisab (minimum threshold) and a hawl (full lunar year) passes over it. A Muslim should pay zakat on all the wealth they possess when one hawl has passed over the first nisab they acquired, even if a hawl has not yet passed over some of the wealth. This is to facilitate ease for the zakat payer and to benefit the poor. Profit does not initiate a new hawl; rather, it follows its principal amount. Zakat can be paid for each currency from its own kind or from a single currency. It is preferable that it be from the currency most beneficial to the poor.