Formula One's governing body approved a proposal to switch the date of next year's Monaco Grand Prix to May 16 on Wednesday but left a question mark over the Canadian and British races.
The International Automobile Federation (FIA) said in a statement that the showcase Monaco race had been moved forward a week after agreement by the World Motor Sport Council meeting in Paris.
It added that it had also approved in principal a request to swap the dates of the Brazilian and Abu Dhabi Grands Prix, pending agreement with the promoters.
That would make Brazil the season-ending race next year rather than Abu Dhabi, which makes its debut on the calendar next week in this season's finale as the sport's first day to night race.
"The FIA is expecting confirmation from Formula One Management about the Grand Prix's in Canada and Britain shortly," added the governing body.
The British Grand Prix is due to switch to Donington Park from Silverstone.
However, commercial supremo Bernie Ecclestone has given organisers until next Monday to provide the required financial guarantees or lose the race. Silverstone is expected to take over if Donington is in breach of contract.
Canada, dropped this year, has been pencilled in for a June 13 return to Montreal subject to contract negotiations, which remain ongoing.
Monaco was moved forward after teams said the later date posed too much of a logistical headache with Turkey scheduled the following weekend.
The FIA said the final calendar would be published in December.