The title comes from the words dulces horas de ayer (sweet hours of yesterday) in the soundtrack song Recordar (To Remember) sung by the soprano Imperio Argentina.
He is obsessed by it, by memories of the older father who went off to Argentina with another woman and the lovely young mother who then committed suicide.
Juan slips in and out of the acted reconstructions and his own not necessarily reliable memories of childhood during the Spanish Civil War and its aftermath.
The film was reviewed by Pauline Kael in The New Yorker; " This movie has the kind of subtle obviousness that is generally described as literate.
What it comes down to is that Carlos Saura has a feeling for dark, autumnal elegance, and a dexterous technique that he puts at the service of tired ideas.