día is masculine in Spanish.
day (any period of 24 hours); day (a period from midnight to the following midnight); day (rotational period of a planet); day (the part of a day period which one spends at work, school, etc.); day, daytime (the part of the day between sunrise and sunset)
“El resto della concluían sayo de velarte, calzas de velludo para las fiestas, con sus pantuflos de lo mesmo, y los días de entresemana se honraba con su vellorí de lo más fino.” — The rest of it went in a doublet of fine cloth and velvet breeches and shoes to match for the holidays, while on week-days he made a brave figure in his best homespun.
Synonyms: jornada
Antonyms: noche
Inherited from Old Spanish dia, from Vulgar Latin *dia, first-declension reshaping of Classical Latin diēs, from Proto-Italic *djous, from Proto-Indo-European *dyḗws (“heaven, sky”). Compare Old Occitan dia and Old Galician-Portuguese dia. Not cognate with English day.