The kick-off of the first game of the new season between Girona and Rayo Vallecano is scheduled for Fri 15th August.
Real Madrid's game against Ossasuna will take place slightly later, on Tue 19th, but there's seems to be some controversy with that game. Apparently Real and Atletico had an agreement with the Association of Spanish Footballers that, should any of them reach the quarter-finals of the FIFA Club World Club, their opening La Liga games would be postponed to later terms. But, despite Real reaching the semi-final, La Liga president, Javier Tebas has stated that Real's request to postpone the game was officially rejected.
More info here:
https://www.goal.com/en-us/lists/real-madrid-xabi-alonso-massive-blow-la-liga-opener-against-osasuna/blte9c595784207f1d3Yes, the point is, Real Madrid must be prepared for all the consequences of participating in the World Cup. So, don't feel like their team has reached the semifinals of the tournament and they can make a deal that benefits themselves. Therefore, I agree with this decision. If Real Madrid's request is approved, I think it will clearly be a matter that will tarnish the reputation of the Spanish Football Association. Many will certainly believe that Real Madrid is being given leniency if it is approved. Furthermore, I think even if Real Madrid doesn't make this agreement, they still have time to rest.
Since Real Madrid has already been eliminated from the World Cup, they still have time to rest or take a vacation before the start of next season. The next La Liga season is approximately a month away, and I think Real Madrid has enough time to take a vacation. Since the two or three-day difference isn't much of a difference, I don't think Real Madrid should have done this rather than create controversy.