Is the method of calculating Zakat correct by collecting the delayed wages, then paying the annual Zakat in July after deducting usurious funds? And what should be done if this method is incorrect?

Firstly, Zakat becomes due when the wealth reaches the Nisab (threshold), not from the date it was received. The calculation should be based on lunar months, not Gregorian months, because relying on Gregorian months leads to delaying the payment of Zakat beyond its due time, which is impermissible.

Newly acquired wealth (salary) must be added to the Nisab and Zakat paid on it along with the existing wealth, or a separate hawl (lunar year) should be counted for it from the day it was acquired. It is not permissible to disregard newly acquired wealth and delay its Zakat payment beyond its due time.