The LFP announced it in an official statement
The Spanish Professional Football League (LFP) decided that the games of the two last match days would be played at the same time, in first division as well as in the second to "maintain equality and the purity of the competition." The organisation announced it in the following statement:
"The final two rounds of fixtures in the Liga BBVA and Liga Adelante will kick off at the same time on the same date, which has been commonplace in recent seasons. La Liga is keeping this aspect of the schedule in place in order to guarantee maximum equality for all teams and to saveguard the purity of the competition.
Matchdays 37 and 38 in the Liga BBVA and matchdays 41 and 42 in the Liga Adelante will all take place at the same time, covering all fixtures which could affect the final league standings, whether for the league title, European qualifying places, promotion, relegation or playoff positions.
Dates and kick-offs will be announced in the coming days."
In the last two fixtures, Barça will host Espanyol on the 7th or 8th of May and will visit Granada on the 14th or 15th of the same month.