You can change the time when you are notified about Daily Challenges.
Tap on Daily Challenge in the Play option, it will bring up a calendar for which you can choose. At the bottom of the page will be a "Notify me about future challenges". If that is checked, uncheck it and you will not be prompted any longer. Or, if you want to be notified at a different time, then uncheck the notification option, recheck it and you will be prompted with the spinner to reset a notification time.