What is the zakat on an amount of 5000 pounds that has been held for a year and a half, and is zakat due on the remainder after the passing of a full year? And is it permissible to pay overdue contributions to a family charity designated for the poor from zakat funds, especially since it is an ongoing charity (Sadaqah Jariyah)?

Zakat is obligatory on money if it reaches the nisab (the equivalent of 85 grams of gold or 595 grams of silver, whichever is less) and a hawl (one lunar year) passes over it. The amount of zakat is one-quarter of one-tenth (2.5%). Zakat must be given out immediately after the hawl passes, and delaying it is a shortcoming that necessitates repentance. Whenever a hawl passes and the nisab is present, zakat becomes obligatory. If the amount falls below the nisab, zakat is not obligatory until it reaches the nisab again, and the calculation of the hawl begins anew. It is permissible to put zakat into a family fund, provided that the fund manager is informed that it is zakat al-mal to be spent on its legitimate beneficiaries as specified in the Holy Quran, and giving it to needy relatives is better.