Take a look at the English version:
```javascript
meridiem : function (hours, minutes, isLower) {
    if (hours > 11) {
        return isLower ? 'pm' : 'PM';
    } else {
        return isLower ? 'am' : 'AM';
    }
},
```

I think you may want to do the same (becuase you used the `i` flag in the RegExp).