quotidian (adj.)

mid-14c., "everyday, daily," from Old French cotidian (Modern French quotidien), from Latin quotidianus "daily," from Latin quotus "how many? which in order or number?" (from PIE root *kwo-, stem of relative and interrogative pronouns) + dies "day" (from PIE root *dyeu- "to shine"). Meaning "ordinary, commonplace, trivial" is from mid-15c.