Formula One has scrapped plans to hold the Turkish Grand Prix in June due to COVID-19 travel restrictions, and announced Austria would host two races in a row, with the French Grand Prix moving forward a week.
The French race at Le Castellet, will now be on June 20, kicking off a 'triple header' of three Grands Prix on successive weekends.
The Red Bull Ring will host the newly-inserted Styrian Grand Prix on June 27 and the Austrian Grand Prix on its original July 4 date.
"We were all looking forward to racing in Turkey but the travel restrictions in place have meant we are not able to be there in June," said Formula One chief executive Stefano Domenicali.
"Formula One has shown again that it can react quickly to developments and find solutions and we are delighted that we will have a double-header in Austria meaning our season remains at 23 races."
Turkey's Istanbul Park circuit had been added to the calendar only last month to replace the cancelled Canadian Grand Prix in Montreal on June 13.
Its removal comes a day after the Champions League soccer final between English sides Chelsea and Manchester City was switched from Istanbul to Portugal.
Turkey was last week put on Britain's travel 'red list', creating a problem for Formula One with seven of the 10 teams based in England.
The red list designation means travel to Turkey is allowed only in "the most extreme circumstances" and anyone returning has to pay for compulsory hotel quarantine.
The race was due to follow on immediately after the Azerbaijan Grand Prix, but that race in Baku now stands alone.
Formula One said Turkish GP organisers had asked the sport to consider holding the race later in the season, should that be possible.
China's race in Shanghai is in a similar position, not officially cancelled but also not on the calendar.
"We continue our talks with the Formula One management and our preparations without letting up, and we are always ready for a race," said Vural Ak, chairman of the Istanbul circuit operator Intercity.
"The Formula One leadership is also very keen on holding a race here. We hope to repeat the honour we had in Turkey last year again this year."
Austria opened the season in July last year when it also hosted two races in a much-reduced 17-round calendar limited to Europe and the Middle East.
French Grand Prix managing director Eric Boullier recognised the date change would have an impact on spectators and commercial partners.
He assured ticket holders that bookings remained valid for the new dates, with refunds available for those unable to attend.
Formula One said 17,000 COVID-19 tests had been conducted this season up to last weekend's fourth round in Spain with 15 positive cases, a rate of 0.1 percent.