I've been seeing many of similar cases in other communities, but yet to happen on my iPhone.
The solution to the problem seems disabling notification for certain apps. Also, the problem seems date specific. Many people changed their date and/or disabled automatic time/date update to solve the problem.
Try disabling notification for your apps. Other than that, try change your date. As many people has claimed various methods for the solution to their problem, I honestly do not know what's real problem. Hope this helps.