Unlike Premier League, football stadiums have closed for the year in Spain. After last weekend, matchday 18, the season won't return until mid-January, 10-13 January 2025, for matchday 19, which will mark the halfway point of LaLiga EA Sports, and would define a "winter champion".
However, there are some caveats. First, due to the floods in Valencia, a match between Valencia and Real Madrid meant for October has been pushed back and will be played on Friday January 3.
Matchday 19, from January 10 to 13, will be played alongside Spanish Super Cup (played in Saudi Arabia, because money). Therefore, the four participant teams, FC Barcelona, Real Madrid, Athletic Bilbao and Mallorca, already played their respective matches earlier in December.
That means that, as of right now, most teams have played 18 matches, except for Barcelona, Athletic and Mallorca, who have played 19, and Valencia, who has only played 17. Bad news for Barcelona, which lost the leadership of the Liga to Atlético de Madrid (41 points) and Real Madrid (40 points), both with 18 games played, meaning they could go even further.
In short, these are all the dates:
Matchday 12 - January 3: Valencia vs. Real Madrid
Matchday 19 - January 10-13: All teams except for Real Madrid, Barcelona, Athletic and Mallorca
Matchday 20 - January 17-20: All teams
On the other side of the chart, Valencia, traditionally one of the largest teams in Spain, the only other team besides Madrid, Barça and Atleti to win the Liga this century, is facing a terrible crisis, sporting, financial and institutional, and is antepenultimate, having only won two games so far.