How is Zakat calculated on money deposited in an Islamic bank, and is it due on the principal amount or on the principal amount with the profits? Is it obligatory to pay it when one is in need of money to buy an apartment, and is it better to pay it in advance or delay it? Is it permissible to give a portion of it to someone who washes cars or to a relative to fix his car, and what is the obligatory percentage for Zakat?

Zakat is obligatory on saved money if it reaches the nisab (minimum threshold) and a full lunar year (hawl) passes over it. Any profits generated from it are added to it, and one-quarter of one-tenth (2.5%) of the total is to be given as zakat. Saving money to buy an apartment or intending to borrow does not prevent the obligation of zakat, unless the borrowing actually takes place, in which case the debt is deducted according to the majority of scholars. It is not permissible to delay zakat after it becomes due; rather, it must be paid immediately upon the completion of the hawl. It is permissible to pay zakat in advance to give it during Ramadan, but it is not permissible to delay it for that reason. It is permissible to give zakat to the needy whose income is insufficient to cover their basic needs, and to those who need to repair their essential car and are unable to do so, if their need is highly probable.