Is it permissible to spend zakat on a son whose father refuses to support him, and is it permissible to pay zakat in installments provided that it is paid in full a sufficient time before the second year (hawl) is due?

Zakat becomes obligatory on saved money if it reaches the nisab (minimum threshold) and a full hawl (lunar year) passes over it. Its obligation ceases if the money is spent before that. The father is sinful if he withholds financial support from his children, for Allah will question him about this action. The children might resort to unlawful means to meet their needs, and the father bears the consequences of that. The father is obligated to provide for his children; he is a guardian and responsible for his flock. The wife has the right to claim back the financial support from the father and demand what she has spent. She may take what suffices her and her child from his money in a reasonable manner, even without his permission, if he refuses to provide support. It is not permissible to give to a child from the mother's Zakat money.