Crontab没有运行重载页面的javascript

I have a php file that send emails to our clients who are expecting it and to ease the load on the server and to eliminate it looking like a spam server we reduce the flow to 40 emails every 20 seconds. This is done by using javascript to rerun the page every 20 seconds. The page itself reads from a data base and gets the next 40 email addresses, sends them, and then recycles until all are sent. Then the email list is reloaded from a duplicate table for the next cycle three weeks out.

Here is the javascript code that seems to not run when initiated by a cron job

<script language="JavaScript" type="text/javascript">
            setTimeout("location.href = \'PT_enrollment.php?sendDate='.$sendDate.'\'",20000); // milliseconds, so 10 seconds = 10000ms
            </script>

When I run this from my browser it does run correctly so I guess it is in the Cron Job functionality.

What am I missing? Is there a setting or parameter I need to set in the crontab or on the server so it runs correctly?

You could just have your PHP process sleep for those 20 seconds:

$emails = // retrieve all emails from database
$done = 0;

foreach ($emails as $email) {
    // send email to $email

    $done++;
    if ($done % 40 == 0) { // every 40 emails
        sleep(20); // wait 20 seconds
    }
}

Ordinarily, cron jobs are run server-side via php-cli, which by default doesn't have a timeout. Some hosting providers run cron jobs by actually retrieving a URL via wget or curl, in which case you do have to account for a possible timeout. In that case, you can add set_time_limit(0); to your script to work around that.

I don't Know how you are running This .. The server will not run JavaScript if you added your JavaScript to file test.php you can run something like

file_get_contents('https://yourdomain.com/test.php');

This will hit the file like you run on browser

or rewrite your Task on PHP language like

$url = 'https://yourdomain.com/PT_enrollment.php?sendDate='.$sendDate;
file_get_contents($url);