Max Verstappen's third Formula One world championship could be sealed in a Saturday Sprint in Qatar, a rare turn of events for a sport more used to seeing its crowns secured on a Sunday.
It is not unprecedented, however.
Brazilian Nelson Piquet, a triple world champion in the 1980s and father of Verstappen's partner Kelly, won two of his titles on a Saturday and the other effectively on a Friday.
Piquet's first in 1981 came at the final round of the season in Las Vegas on Oct. 17, a Saturday.
The second in 1983 was clinched at Kyalami in South Africa on Oct. 15, another Saturday race.
The Brazilian was assured of the 1987 title in Japan when Williams team mate and championship rival Nigel Mansell, who would be champion in 1992, suffered a season-ending crash on the Friday at Suzuka.
Piquet ended up taking no points from the final two races in Japan and Australia but that no longer mattered once Mansell was sidelined.
The very first world championship grand prix at Silverstone in 1950 was held on a Saturday, in the presence of royalty, and the British Grand Prix continued to be held on that day of the week until 1977.
The last full-distance world championship race to be held on a Saturday was the South African Grand Prix of 1985, won by Mansell.
Saturday's 100km sprint in Qatar offers Verstappen a first chance to score the three points he needs to wrap up the championship.
Eight points go to the winner, down to one for the eighth-placed finisher.
If Verstappen, winner of two of the three sprints so far this season, finishes sixth on Saturday then Mexican team mate and sole title rival Sergio Perez will be mathematically out of the running.
Verstappen leads Perez by 177 points with 180 remaining to be won from the final six rounds and 146 after Qatar.
Perez has to finish at least second in the sprint but even if Verstappen fails to score on Saturday with the Mexican winning, the title will go to the Dutch driver on Sunday if he comes eighth.
There is every chance of more titles being won on a Saturday in future.
Three grands prix will be held on that day next year -- Bahrain and Saudi Arabia early on to accommodate Ramadan while Las Vegas will be the 22nd of a record 24 rounds -- and there will also be six Saturday sprints.
This year's Las Vegas Grand Prix on Nov. 18 will also be a Saturday night race.
Races have been held on Mondays and Fridays too in the past, sometimes to avoid fixture clashes or simply in the hope of attracting a bigger crowd on a public holiday.
That was the case in Spain in 1972, when the race at Jarama was contested on the Monday of May 1.
(Reporting by Alan Baldwin, editing by Christian Radnedge)