Assalam o Alaikum,

I hope you are well and staying safe. My name is Dr. Ghulam Muhammad Memon. I give a part of my salary to my father every month. My father dutifully pays zakat on that money every year during the month of ramadan. Due to some financial difficulty I have not been able to provide that monthly amount to my father for the last 10 months, and will not be able to do so for the next 8 months. Once I am able, I will give the money for all 18 months to my father. My father would like to unnderstand that since he does not have that amount in hand at the moment and ramadan is around the corner, is he required to pay zakat on that amount?

Thank you very much!! 

-Ghulam Muhammad Memon