Didn't anyone look at TheOhioBloke's post?? As of Dec 2 @ 00:15 local time
https://www.macrumors.com/2017/12/02/ios-11-1-2-date-bug-crash-loop/
Turn off Notifications, upgrade to 11.2, turn Notifications back on.
https://www.macrumors.com/2017/12/02/ios-11-1-2-date-bug-crash-loop/
Turn off Notifications, upgrade to 11.2, turn Notifications back on.