The date is not fixed because of the Spanish Supercup games
Barça plans to organize the Joan Gamper trophy the first week of august. According to Miguel Rico at Mundo Deportivo today, where he said that the club has the intention of celebrate the 50th edition of the tournament, although the former director ( Antoni Rossich) decided to eliminate the competition.
Rico said that the club has talked with "a good team", but the situation with other competitions during the pre-season is difficult to confirm the rival. The problems are the dates for the Spanish Supercup.
Barça already knows that the European Supercup will be august 11th in Tiblissi, the capital of Geòrgia. And the 2nd of august will play a match in Napoli, after the american route. The intention of the club is play the Gamper between this two dates, but they don't know the dates ( because of the television contracts).
Athletic of Bilbao has to play the previous round of Europe League, the 30th july and the 6th of august. And if they pass to the second round the will play the 20th and the 27th of august. This has to be coordinated with the beginning of the season, and the LFP wants to put the games the weekend of the 15-16th of august.
Barça has demanded the dates of the Supercup (if it's possible this week better) because when the know the dates the will plan and confirm the rival for the Joan Gamper tournament.