The poster before me, as far I am understood, asked a question.
You can factually say 73 mins is gone. Or 21 mins of the 2nd half is gone, or whatever.
You do not at that point know how long is left though, so the answer to how long is left, cannot yet be factual. Even with what you deem to be 1 minute left, there could be an injury, a goal,, 3 subs, some time wasting, a pitch invasion, anything, that might act as a variable in how long is left to play
I actually think you are aware of this but wanted myself to spell it out to prove your previous point re my posts.
Players aren't generally stupid with time, winning or losing they will want more or less whatever is in their favour.
Time is time whenever we see fit. The closer we get to normal 45 or 90 minutes I always added 'plus stoppage' to and time quoted whichever way.... After 70 minutes or so, it doesn't really matter, as it winds down it does in their minds, so add the 'plus extra time' or something comment as you see fit.. Its a none issue really!!!
Stop trying to get all philosophy 101. Yes, you do know how long is left.
How long is left is 13 minutes. Plus stoppage time. That's a fact. As factual as the other answer.
You state plus stoppage time an Oh Look! You've included the variable portion and every player knows exactly what you mean.
And usually players want you to answer 'how long' rather than 'how much have we played'. Because at that point they're probably too tired for mental arithmetic. Assuming they could ever do it ;-)