and for every Saturday in January:
https://www.northernrailway.co.uk/strike
https://www.rmt.org.uk/news/rmt-confirms-raft-of-new-strike-dates-on-northern-rail191218/
As usual, all Barton line services should run, but people at Cleethorpes, Grimsby and Habrough note that the Brigg line trains will not run.
https://www.rmt.org.uk/news/rmt-suspends-northern-strike-action/
Industrial action now suspended, it seems agreement has been reached to have a guard on every train.