I don't know of a way to do eactly what you are asking, but I have suggestion that might be suitable for your situation. You could simply delay attempts between restarts to make it never try to restart once every 15 minutes. To do this, you would simply add 'with timeout 900' to the end of your 'restart = /etc/init.d/apache2' line (or what every your restart line is. This will cause apache to still get checked every cycle, but never try to restart more than once every 15 minutes.
Like I said, it's not exactly what you were asking for, but it seems like it might serve your purpose.