I have a maid who will clean my condo twice a week. I pay her at the end of her 4th week (8th times). I can easily schedule an event on iCal to alert me a couple of days before that 8th day since it will be the exact same day of the week. But she may ask me for a day off and then everything will change. So now she will not work on, say, Monday but will begin instead on Thursday. This way the day I pay her will be moved to different day of the week. Now I know I can move the event and all afterward a few days after but will the alert also moves? And how exactly to set the alert?