I am planning a train trip in Scotland from roundabout Aberdeen to Thurso on December 29th and have noted that the cheaper 'advance single' tickets can only be bought up to December 23rd. I first thought that the tickets may have been already sold out between Christmas and New Year, but there are also no advance tickets available for later dates in January.
The absence of advance tickets starting on December 24th has been so for about a week, so it does also not seem to be the case that the tickets can be bought within a fixed period, e.g. 6 or 7 weeks before travel.
Does anyone know if at all and when ScotRail advance tickets will be available for sale for trips on December 29th? According to a few arbitrary tests on nationalrail.co.uk, advance tickets from other train operators seem to be available for the relevant period.
Just for completeness: I am not able to reach ScotRail by phone. Whenever I call, all lines are busy and I am told to hang up and call later. When asking in writing, I got a response that advance tickets are not available yet after the time table change in December. Since the time table change is on December 12th and advance tickets can be bought up to December 23rd, this answer does not really make sense.
Edit: Just a screenshot to accompany my comment to barrowc.