“Respected sir, I retired from the Air Force as a JWO on 30th November 2020, holding the rank for two months. However, my pension is being calculated based on the rank of Sergeant. I understand there’s been a change allowing pension based on the rank held for even a single day. Is this true?”

Yes, there has been a change in the pension calculation rules. As per the revised rules, pension is calculated based on the last rank held even for a single day. You are entitled to pension based on the rank of JWO, as you held it for two months. You should contact the concerned authorities and provide them with proof of your rank to rectify the issue.