Awards that are based on Scenarios (X Kills in the Scenario, Purple Hearts, etc.) are awarded at the end of the month.
Promotions and Retirement rolls are all at the New Year and all enlisted ranks are based on skills, Officer ranks are based on who I want to lead the lance/company/battalion/regiment (skills play a huge part in this, but they are also the "main" stars of the force). Ranks go from E0 to E13 for warrior ranks, E0 to E9 for non-combat, WO1 to WO5 (non-combat) and O1 to O5 (combat) for officers.
E0 to E4 are ranks for Astech and MedTechs - the Astech/MedTech skills go from Rank 0 to max Rank 4, each skill level determines their rank E0 = Rank 0, E1 = Rank 2, etc.
Enlisted (warriors) go start at E2's when newly recruited, then with the New Year's promotions go from E5 to E13 (skill ranks 0 to 9, calculated on average for Gun/Piloting when used)
Non-combat (Technicians, Doctors, and Admin) go from rank E5 to E9 (Primary Role skill Rank 0 to 4) and Warrant Officer ranks WO1 to WO5 (Primary Role skill rank 5 to 9)
Officers are determined by their hierarchy. I max out at O5 (Lieutenant Colonel in my ranking for Mechwarriors), so the leader of the force/group will be O5 (MechWarrior CO, Aerospace CO, Vehicle CO, etc. I run a merc unit, all the CO's have equal say in contracts and such, but recognize the Mech CO as leader among equals). There are officers among the Technicians, Doctors, and Admins as well, so my force has CO's from Mech, Aerospace, Vehicle, Infantry, Transportation (Jump- and DropShips), Technician, Medical, and Administration (8 on the board of CO's, Mech CO being the overall leader/face).
CO's are level O5, Regiment/Wing commanders are O4, Battalion commanders are O3, Company Commanders are O2, Lance Commanders are O1.
So, a company will comprise of 2 O1 commanders and their senior O2 commander.
Battalions are one O3 commander, two O2 commanders, and six O1 commanders
Regiments/Wings have a command lance with a O4 command (or an O5 command if integrated, a command lance/wing with an O5 commander if not integrated).
Non-combat CO's are that singular character chosen by the story.