(Yesterday, 4:30 pm)stagecoachbusdepot wrote Still just says times TBC from what I can see https://www.durham.gov.uk/DurhamExplorer but great if they are on the operator website now, they weren't earlier. Hopefully will be a success.
I get the same showing on that page linked, but they're on the Durham County Council timetable site (although I was having difficulties opening the 875 timetable) and Northstar's own website.
Looks as if services 874 & 875 will interwork at Durham from looking at the timetables.