Google Now keeps on top of you so that you can remember to do your chores
You can set the reminders to go off "today", "tomorrow" or "occasionally." The first two are not recurring reminders, but the third one is. If you choose to have an event pop up occasionally, it will go to the top of your Google Now cards stack. When these reminders pop up, you can dismiss them or postpone them for another day.
Google won't reveal how many days until a postponed event comes back around to remind the user about the particular chore that needs to be done. It is just another way that Google Now tries to get information to you, when you need it the most. In this case, the app is warning you to get something done before you feel the impact of a rolling pin aimed at your head.
source: GoogleNow via AndroidPolice