I'm getting ready to run a new campaign in a few months. One of the things that one of my players brought up to me is that he'd like to see the passage of time tied with character progression as it's been portrayed in the fluff. I was considering putting limits on rank attainment and talent development (i.e. none during an adventure) as well as alternate career paths. However, even then I'm not sure if that will work (except for the progress along alternate ranks).

I'm curious as to how other GMs have approached this or reasons why other GMs decided to not use pasage of time.

Our GM uses the Joss Whedon's Speed of Plot from Firefly. Namely anything takes as long as plot dictates.

If we need to move quicker for some reason, warp travel works in our favor, we spend extra time training while traveling, traffic lights all turn green, there is no traffic to be found, and we're in luck that customs bumps us to the front of the line.

If for some reason the GM needs extra time, we hit a warp storm or it doesn't work in our favor, our ship becomes tempermental and takes all our time trying to keep it up and running, all the traffic lights turn red, a parade celebrating some local saint is blocking the traffic, and customs wants to be complete asses and body cavity search everyone and our ship before letting us through and is constantly loosing paperwork.

So character progression based on in game time becomes kind of difficult too, when one time travelling and your characters are totally bored allowing a lot of sparring and training time during that trip, while the next time your characters are completely busy trying to pick up leaks and put out fires.

In another case, your character wants a talent that requires and inplant and happens to be doing a mission in the Lathes, making said inplant impossibly easy to find, while the next time he's on some backwater feral planet, making it impossible to find.

the issue is of course is that generally you issue xp in a per session basis, rather than game time. I suppose you could give say, 100xp per month of game time, or whatever. but the character development would become kinda 'lumpy'.

I give 100xp per session, and a bit extra at the end of each mission. During extended periods of down time I let characters determine how they spend their time, and give them skills, talents or stat boosts based on what they did.