Q:

I want the time left on the map to be displayed on my HUD

Is there any console command, setting or trickery to make this happen? 

A:

I think (but not sure) this is a server or mod option as when I was trying to practice (little good it did), sometimes it was displayed in one of the top corners. 
The only way I know of to do it yourself is to go in to options > keyboard, and then map a key to Time Remaining or similar.  When you press this key, it displays (near chat/text) how much time is remaining.