Looking into it now

, thought I saw a few lines of code dealing with retirement...
Edit: Find your career save file in your documents folder (...My Documents\SH4\data\cfg\SaveGames\(YOUR SAVE FOLDER). When you open the Careertracker files in each folder, under the CareerStatusLast section the date should match the date last shown on the calender in your "lobby" room. Once you verify that you have the correct Career Tracker file, try changing some code:
Look at an example from one of my save files:
[CareerTrack 1.CareerStatusLast]
ID=ID
Reason=CSS_LastStatus
NameDisplayable=NULL
CurrentDate=1942-01-05 03:08:14
PlayerRankAchieved=LTCDR
PlayerCurrentLastPromotionDateTime=1941-12-08 16:00:00
CurrentFlotilla=PearlHarborCommand
CurrentFlotillaBase=PearlHarbor
CurrentSDepartureDescription=-1.89576e+007,2.54882e+006,242.189
CurrentUPCFlotillaUserPlayerUnitType=F1Tambor
CurrentDifficulty=Hard
PlayerCurrentRenown=4548.399902
PlayerCurrentRating=1.000000
PlayerHighestRating=0.000000
PlayerPatrolsCompleted=0.000000
PlayerTonnageSunk=9398.000000
PlayerWarshipsTonnageSunk=0.000000
PlayerMerchantsTonnageSunk=9398.000000
PlayerShipsSunk=0.000000
PlayerCurrentMedals=NULL,Bronze Star
CrewMembersCurrentMedalsRepository=NULL,Bronze Star,Bronze Star
CrewMembersCurrentPromotionsRepository=5
PlayerCurrentObjectiveCode=Marshall Islands
PlayerDefaultObjectives=ID94
PlayerCurrentObjectives=ID80
PatrolStartDateTime=1942-01-25 08:00:00
Player current rating seems to get higher after each patrol. Try reducing the number next to Playerrating to 1 to see if you dont retire. I dont know if it will work since I havent had to retire in any of my careers yet, but it is worth a try...