How can a PHP script be scheduled to run regularly, such as at a specific time each day, without user interaction?

To schedule a PHP script to run regularly without user interaction, you can use a cron job on a Unix-based system or Task Scheduler on Windows. These tools allow you to specify the time and frequency at which the script should run.

// Example PHP script that can be scheduled to run regularly
// This script will output 'Hello, World!' to a file named output.txt

$file = 'output.txt';
$message = 'Hello, World!';

file_put_contents($file, $message, FILE_APPEND);
```

To schedule this script to run daily at 8:00 AM using a cron job, you can add the following line to your crontab file:

```
0 8 * * * php /path/to/your/script.php