Be aware that max_execution_time can be altered by XDebug.
While debugging a script locally that made use of <?php ini_get('max_execution_time'); ?> it returned 0 when XDebug remote debugging was enabled and the IDE was listening to it.
It makes sense, since debugging manually takes time so we don't want the script to time out ; but in that particular case, it made it look to the script like max_execution_time was 0, so calculations were wrong.
You can see in phpinfo() that local value is 0 in that case, but master value is the correct one you set in your php.ini.
