When you are in-game, you can click on the game time, and it will tell you how many real life minutes are left of game time.
From outside the game, it tells you the game time BUT it doesn't give RL minutes left. As it is, where it says "game time" it is rounded to the previous hour. Right now my screen says game time 10pm, but when i mouse over it it says 10:51pm. It would be hella helpful if the real life minutes left was displayed on mouseover, and the game time listed was the actual game time and not rounded to the previous hour.
I am currently working on the badges that require you to max out your quoins every game day that you log in. This means if I'm unsure of how long I have left in the game day, or if the time is too short, I shouldn't log in.