I'm guessing area code relates to telephones, or maybe postcodes/zip codes, don't know.
Using Ab's idea of binary I'll offer the following.
The hidden code
For which you seek
Is in the hours
Any day, every week
Maybe binary
Seems to be
The little clue
That holds the key
To show the place
Your calls will go
Maybe thats all
You need to know.
Substitute MAIL for CALLS if I've made a goof.
rgds.
Hope you have fun with your game.