More info on the Durham service changes, info from one of their drivers (journey planner on the app confirms all this).
22/23/24 - Interworking with each other. 23 now extended to Hartlepool Marina, whilst also serving Dalton Park now. 23 upgraded to Sapphire spec.
43 - Timetable changes
56 - Later journeys to compensate for the loss of the X12 after 2000. Will operate a different route around Stobb Cross, now turns left onto Linden Road (as per the Sunday route) and then left Laburnum Road.
57/57A - Timetable changes
X12 - as Kuyoyo states above
X46 - Timetable changes
Arriva North East: Upcoming Service Changes