Anger is mounting at plans to cut 700 ScotRail services from Monday.
One Scottish politician has warned the move by the nationalised train operator would have a "profound" effect on businesses and passengers.
The BBC says the temporary timetable is being brought in because of a driver shortage caused by a pay dispute between ScotRail and the Aslef union.
It will see the last train on many routes departing before 8pm. The last train from Aberdeen to Inverness will leave at 6.18pm. However, services will run as far as Inverurie at 7pm and 7.57pm.
ScotRail was nationalised by the Scottish Government last month after the previous operator, Abellio, had its franchise ended early amid criticism of the quality of the service.
This month's timetable had approximately 2,150 weekday services, but these are now being reduced by a third to 1,456.
Hundreds of trains have alreday been cancelled since May 8 when many drivers opted not to work overtime. Drivers' union Aslef had balloted members for strike action after rejecting a 2.2% pay offer.
Similar cuts are expected to be made to the Saturday and Sunday timetables, with details due to be made public in the coming days.
During first minister's questions at Holyrood, Nicola Sturgeon said it was vital to get rail services back to normal as quickly as possible, with the timetable to be formally reviewed on June 3.
But she said an agreement on fair pay would need to be reached with rail workers before the timetable could be reinstated.
Additional drivers were also being trained up, she added.
"I expect ScotRail to make sure that this temporary timetable is just that - temporary - and the timetable gets back to normal as quickly as possible," said Ms Sturgeon.
She also urged Aslef and ScotRail to continue negotiations to reach a settlement.
The first minister added: "I would say to the unions that I understand their job is to represent their members and to get a fair pay deal for members, but let's see both parties get round the table and negotiate that in good faith - I think that's what the travelling public want to see as well."
Scottish Conservative leader Douglas Ross said passengers were now paying more than ever in fares and getting the worst service seen for a generation.
He also said the reduced timetable would have a profound impact on businesses as well as passengers.
Mr Ross said: "Last month, the first minister proclaimed that nationalising ScotRail was a new beginning that would deliver a railway for the nation.
"But after just seven weeks, nationalisation is already proving a disaster.
"These cuts will also be devastating for businesses still reeling from the impact of the Covid pandemic. They are facing another lost summer."