Champions Barca will host Real, who top the standings by a point from their arch-rivals after 10 games, for the match at the Nou Camp at 8pm GMT, the LFP said.
The decision had been taken to avoid "the security problems that the coincidence of the two events on the same weekend could cause," they added.
Last season's two 'Clasicos' were a key factor in deciding the outcome of a league totally dominated by Barca and Real and the same is likely to happen in this campaign.
Barca won both last term, edging the match at the Nou Camp 1-0 and winning 2-0 in Madrid, and pipped Real to the title by a record 99 points to 96. Valencia were third on 71 and Sevilla fourth on 63.
Manel Arroyo, a Barca director responsible for finance and marketing, told the club's television channel they would have liked the match to have been a day earlier on the Sunday but they understood the reasons for the decision and accepted it.
"We asked for it not to be on the Saturday and we would have preferred it to be on the Sunday but we understand that the schedules of the authorities, the security services and the television companies were chock full," he said.
Barca coach Pep Guardiola, now in his third season, has led his team to victory in all four 'Clasicos' since he took charge, including a 6-2 drubbing of Real at their Bernabeu stadium in May 2009, while Jose Mourinho will be experiencing his first as Real coach.
The return match at the Bernabeu is the weekend of April 16/17.
