I have been scouring the rulebook and I can not find much information about time. I understand the combat time aspect, but when a certain action states it takes about 10 minutes to complete or when a certain item won't be available for a year, what does this actually mean in terms of game play?

I am new to GMing and am sorry if this is a dumb question.

Time takes in-game as long as the GM want's it. Think of it as time in a movie, where sometimes several seconds can slow down quite heavily (like in slow-motion or "bullet time"), and sometimes several years can be sped up to a matter of minutes.

It's what you'd call "narrative time". And anything in game will take exactly as much real world time as you need it to take. Hope that helps you.

I keep a GM's calendar for this game, as in-game time seems to matter. For Dark Heresy, it didn't, so I didn't bother.

As far as adventures go, I just sort of guesstimate on my GM calendar. Keeping track of time down to the minute is boring and unnecessary unless there's a particular situation like "the players have 10 minutes to find and defuse the bomb".

But in this game, years and months can go by quite quickly even in a single game session especially when PC's are doing extended actions like docking to improve Ship Morale, waiting at Port Wander for a Ship Component to be installed, etc.