Yes, this is true; you should determine the beginning of the Khums year, which is a set date ever year. For the past period in which the Khums has not been paid, you will need to agree with your Marja or his agent on an appropriate set date and to calculate the due Khums accordingly. Additional to this, you will need to pay the Khums of all unused items in your possession, include money you have in your hands as cash and what you have saved in the bank. Once the due Khums has been paid, you are left with 80% of the original amount. Khums will not be paid on this 80% remainder again, and you are to calculate the next Khums payment on any further savings at the next set date.
