Pensions were paid quarterly in arrears.
Applying for service records to the National Archives is usually a waste of time. Records of this period are filed on microfilm, and they will not look on a roll for a single set of records. Most are now on Findmypast anyway. If you post his name, or a link to where you found them, someone will help you find them on Findmypast, and you can download them for a few credits.
Ken