one-hit wonder

blonde hair and blue eyes (used to describe Europeans.)

Xueyantuo (ancient Tiele Turkic people and Turkic khanate in central/northern Asia)

each person has one life, regardless of social class or circumstances

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

a birthday

regular day off (e.g. closed every Monday)

the twentieth day of the month / twenty days / Short for 二十日鼠 (hatsuka nezumi): a house mouse

幾日も幾日も: day after day

many a true word is spoken in jest; words spoken in jest may come true (often by accident)