What is date of supply for Periodic payments Or Consecutive invoices

In a case, where commerical property rented out for 3 Years and payment terms are quarterly in PDC mode & collected. A single Tax Invoice issued for 3 years in advance & tax calculated accordingly and paid to authority.

Is this right treatment under Article 26 of VAT Decree? Or Tax Invoices should be issued on annual basis becuase periodic payments are receiving.