When does the hawl for zakat begin for an agreed-upon and guaranteed amount that is paid in installments: from the date of the agreement or from the date the full amount is received?

Grants are gifts that are not owned except by taking possession of them. Their hawl (zakat (definition) year) begins upon their actual or constructive possession. The hawl for each installment begins upon its possession, provided it reaches the nisab (definition). As for allowances: if they are wages, they take the ruling of a salary, and zakat is obligatory on them, along with their hawl. If they are grants, they take the ruling of grants.