You don't get any push notification?
Go to [Menu] - [Option] - [Notification Setting] in game. Check and turn on all notifications that you want.
For iOS, you cannot get any push notification even you turn on all the notification in the game, if notification setting is turned off on your device.
'Midnight notification' is a special option for your sleep. When you turn on the Midnight notification, you will receive the notification for 24 hours. When you turn off the Midnight notification, you will not receive any notification from 11PM to 8AM.