
Latin word diem comes from Proto-Indo-European *dyew-, and later Proto-Indo-European *dyḗws (Sky god. Sky, heaven.)
*dyew- (Proto-Indo-European)
god, sky, sky, sky, heaven
*dyḗws (Proto-Indo-European)
Sky god. Sky, heaven.
*djous (Proto-Italic)
Jupiter. Day, sky.
diovos (Latin)
dies (Latin)
(often in the feminine) A set day: a date, an appointment.. A day, particularly:. A solar or sidereal day of about 24 hours, especially (historical) Roman dates reckoned from one midnight to the next.. Daytime: a period of light between sunrise and sunset.