Question: Is zakat not given based on Gregorian calendar?
Zakat is given based on Islamic lunar calendar, not Gregorian calendar.
Question: My zakat due date is August 10. This year I do not reach nisab due to my debts. However, my husband will buy me a piece of gold jewelry out of his salary after August 15. Do I have to give zakat if I reach nisab when his present is included?
August 10 cannot be ones zakat due date. It must be based on Islamic lunar calendar, e.g., Rajab10, Shaban 7, etc. First, you must determine the lunar date for August 10. For example, suppose that you have reached nisab on, say, August 20. First, you must determine the Islamic lunar date for August 20. If you still possess nisab when this date comes the following year, you must give zakat. If you do not possess nisab then, you must wait until you possess nisab again.