The Royal Spanish Football Federation (RFEF) has ruled that LaLiga games cannot be played on Fridays and Mondays without its approval.
The first three round of matches for the 2019/20 season had already been scheduled by LaLiga, with Athletic Bilbao hosting champions Barcelona in the season opener on Friday, 16 August.
But the RFEF’s competition judge has now rescheduled those fixtures.
“Spanish football fans do not want games on these days,” the RFEF said.
“Especially on Mondays, it is very difficult for fans to enjoy games.”
In February, Alaves supporters held a mock funeral during their La Liga win over Levante in protest at the match being switched to Monday night for live TV coverage.
La Liga said the ruling threatens their 2bn euro broadcast deals and a court hearing has been set for 7 August.
Changes made by the RFEF mean the season will now open with Athletic-Barcelona a day later than originally planned, on Saturday, 17 August, with all other fixtures scheduled for Saturdays or Sundays.
“With this illegal conduct RFEF officials are generating confusion in the national and international broadcast space, which accounts for 2bn euros in annual rights income for La Liga,” said La Liga president Javier Tebas.
“These officials have no idea of the consequences of their irresponsible acts. This has no purpose, nothing will change, this only creates confusion, which is the only thing they know how to do.”
This is the latest in a long-running row between the two organisations.
They clashed over La Liga’s failed bid to play Girona’s home league game against Barcelona in Miami in January, after the RFEF did not give approval for the game.
La Liga called the RFEF’s move “an attack” and said it is “the only competent organisation to set schedules and dates in the national professional football competition”.
It claims the judge’s ruling changes nothing and “the schedules already indicated by La Liga for the first days of the competition will be those in which the matches will be played”.
The RFEF said the judge made the ruling “due to the incompatibilities detected between the approved calendar and the days and established schedules”.
In a statement after Friday’s ruling, the RFEF claimed responsibility for setting the days of the fixtures.
“Setting the schedules is a competency of the League, while the days are of the RFEF,” it said.