What is the hawl (one-year period) considered for zakat on money if money (cash) is combined with gold to complete the nisab, given that the hawl for the gold was 3 months and the hawl for the money was 6 months?

Banknotes are treated like gold and silver for zakat purposes, so they are added to them to complete the net taxable amount (nisab). If someone possesses wealth that does not reach the nisab, and then the nisab is completed six months later with wealth of the same type or another, the hawl (one lunar year) does not begin until the date the nisab is completed. Zakat is not obligatory before that.