Two spies meet in a city, near a cornerstone pillar, on 9/16/16. One delivers a message to the other. It says:
5 4 7.3 9 10 11
9 4 11 9.4 '
1.1 11 11 4
They nod at each other in approval and then meet somewhere to continue their conversation over breakfast.
Where do they meet and when?
Edit: Please read all comments & attempts below. I strongly believe all the necessary clues have been provided.
Edit 2: The bounty expired yet the answer was not given. Hint:
Give special thought to the what the line
12 1means by itself and then in relation to the rest of the puzzle.
Edit 2: I gaze upon this riddle in horror! Especially after reading the sandbox rules. I shan't let it go stale! Hint:
The riddle's tag is cipher. Therefore the numbers in the box map to letters that spell a location. Not geo-coordinates, although that is clever.