(at around 40 mins) There was not a Friday the 13th in June 1991. In 1991 the only months with Friday the 13th were September and December.
The year 1991 had 1 total solar eclipse, which was in July, not June. This eclipse was visible in Latin America and not in Madrid.
When the children first enter the restaurant where Ana (Ana Torrent) is working, she promises Antoñito (Iván Chavero) two Euros. The Euro did not become legal tender in Spain before 1999 and notes and coins were not introduced before 2002. However the film is set in 1991, ten years before. Instead the Peseta was used, and she should have promised ESP 300-400.