title: Schedule e-mail notification 24 hours before certain event?
body: <p>I have a PHP-based site with bookings/appointments stored in a MySQL database.</p>
  
  <p>I want to set an e-mail notification to be sent to each person who made a booking exactly 24 hours before their booking. Bookings are added through a regular PHP form.</p>
  
  <p>I know I could add a script to, for instance, the index page that checks the database for any bookings that are in the final 24 hours, but that's unreliable since I won't be getting much traffic at first. So the index page could go hours without visits, and the notification would be hours late.</p>
  
  <p>The other solution that came to mind is to set a cron job that runs every minute, calls a PHP script which checks whether any e-mails should be sent and sends them. But I'm not sure if this is overkill in a way; does anyone have a better solution than having something run in the background every minute?</p>
  
  <p>To sum it up - is there a way to do this without cron?</p>