The CEO of Formula 1's race in Baku was initially unaware Azerbaijan's first grand prix would clash with the Le Mans 24 Hours next year.
The Grand Prix of Europe was originally handed a July 17 slot when the FIA released the 2016 calendar earlier this year.
When a revision was announced at the end of September, however, the race had switched to June 19, putting it in direct conflict with sportscar racing's most prestigious event.
The only concession for the race is the start time will be scheduled to avoid the conclusion of Le Mans.
With regard to the date change, and whether it was the organisers or FOM that made the switch, race chief Arif Rahimov said: "Basically, we did it together.
"There was a challenge with logistics and we had to think of a new date, and this was the more realistic date."
On the subject of the date clash with Le Mans, he said: "No, we weren't aware.
"But it's a busy calendar and really hard to accommodate to everyone's liking."
The date clash has prevented Force India F1 driver Nico Hulkenberg from returning to the Porsche line-up in 2016 to defend his Le Mans crown with Nick Tandy and Earl Bamber, although Porsche delayed making any decisions on its third car line-up in the hope of another date change.
Rahimov is eager to ensure there are no such issues in the future, adding: "For the coming years we're definitely going to try to avoid clashes as much as possible.
"The date will slightly change anyway from year to year, but we will try to make sure it doesn't clash with any major sporting events, especially motorsport events.
"It's a very unique season in 2016 with 21 races. There has not been a season with that many races.
"It's really hard not to clash with any major sporting event.
"We're clashing with not only Le Mans, but also with the European football championships.
"There is always the possibility of clashing with another big sporting event if you have a calendar of 21 races.
"If it hadn't have been us, it would have been another race clashing with Le Mans."