Excerpt Length?

Just found this later in the support forum. The answer is here: https://gist.github.com/billerickson/1179950

put this file in your functions.php. Works like a charm.

This solution: https://gist.github.com/billerickson/1179950 are not working in version 2.5.1, WordPress 4.4.2

Any idea why does not working? How to change default excerpt from 50 to 15?

Djuka