I used Javascript and no I did not use JSON for anything. I removed all the console.log and it worked. It could be a problem somewhere in codewar's code since the error is at "position 1673101".

Why I'm I getting this error message "Unexpected token { in JSON at position 1673101" when submiting my answer if all local test cases passed.

Time: 442ms Passed: 12 Failed: 0
Test Results:
Some simple multiplications
simple (4 Passed, 0 Failed)
Completed in 15ms

Some corner case
corner cases (5 Passed, 0 Failed)
Completed in 16ms

Some big multiplications
big boys (3 Passed, 0 Failed)
Completed in 27ms

You have passed all tests! :)

[ [ [ '18:02', '18:26' ], [ '19:00', '19:00' ] ],
[ [ '17:32', '18:50' ], [ '19:00', '19:00' ] ] ]

11 min Expected Answer: null;

I understand that the available time from 18:26 to 19:00 is more than 11 min and from 18:50 to 19:00 is less than 11 min therefore is null.

But if all business people are assumed to start from 09:00 to 19:00 isn't it supposed to be 09:00 in this case?
Since one is available from 09:00 to 18:02 and the other from 09:00 to 17:32 both times more than 11 min.
Is there something I'm not understanding from the description?