I got 4 weeks when leaving the Services, that just makes sense, if anyone was going to cause mayhem in their last days service, they have a period where they are still under military rule after they have gone where they could be disciplined.
I know someone who in a none military service was on his last day and was told that he wouldn't be allowed to leave until he cleared his desk of all outstanding paperwork, he did, he shredded the lot and walked out at 5 pm into retirement.