Section 199(4) in The Navy (Pension) Regulations, 1964
(4)When the exact date of a pensioner's death cannot be ascertained, the Controller of Defence Accounts (Pensions) shall have the power to admit arrears of pensions for the entire month in which the casualty occurred, but when the month or year of death is not known the payment of arrears shall be limited to a period of one month.
