The photo is dated January 1956 and must be from the Park's first holiday season, which lasted from November 24, 1955 through January 8, 1956. (Don't get me started on Disneyland's nomenclature for the holiday periods through the years!)
Currently an archivist with the Federal government, I am also (variously) a Disneyland encyclopedist, thesaurer, nomenclaturist and gazetteer. As such, I am engaged in researching all things Disneyland. Nitpicking welcomed.