It is affected by max execution.
You have to create a line in your script which sets the execution time:
Sets 90 seconds.
Extra info: Everytime this line runs, the counter is reset. And only PHP-used-time is counted.
This will run perfect. The only problem in Windows can be Internet Explorer which has some self-defined-max-execution-time before it displays a "could not connect" error. Both Firefox and the command-line will even wait for the full 100 hours and the script wil keep running.
$query="some query that takes about an hour to process";
while ($i < 100);