What should you do when someone tells you "Look up! an attacker is behind y

Question:

What should you do when someone tells you "Look up! an attacker is behind you, 10 o clock!" ?

In the movies, they also say "5 o' clock"

Best Answer - Chosen by Asker:

When someone tells you to look in a direction by referring to time, they mean that you should look in the direction of that hour as indicated on the dial of a watch.

They assume that you are always facing 12 o' clock.

So 10 o' clock means you should look to your front-left and 5 o' clock means you should look to your back-right. Got it?