Section 304(1)(b) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(b)have completed 15 years' pensionable service reckoned up to and for the 14th August of the year in which recommendations are submitted, the last 12 years of which carried a continuous "Very Good" character and with the previous character not inferior to "Good". Where character has been assessed on the sailor's Service Certificates "Good" on 31st December in any year, time reckoning for the Medal shall commence on the 1st January following,