How is zakat calculated on money saved from two salaries (the salary from the home country and the country of study) and house rent, and is it calculated as one sum or separately?

The issue known as zakat on acquired wealth, such as salaries and rental income, requires that zakat be paid on each installment individually, upon the completion of a full Hijri year from its possession, if it reaches the nisab. However, the more convenient and cautious approach is to pay the zakat on all the wealth when the hawl of the principal amount is due, by designating a single day for the obligation of zakat on wealth. This is considered an advanced payment of zakat on acquired wealth, and it is permissible.