Paying the Zakah for the previous years

A 1: It is obligatory to pay the due Zakah for the past years. You should carefully calculate the years and pay the Zakah due on the land as precise as you can in order to clear your father and your dead uncle from sin. May Allah grant us all forgiveness and safety in this life and in the Hereafter.May Allah grant us success. May Peace and Blessings of Allah be upon our Prophet Muhammad, his family and his Companions!