Alternative spelling of oh dark thirty

(music) A note that has 1/32 the length of a whole note.

plural of thirty-second note

(informal) The wee hours.

(chiefly US military slang) Half an hour past 12(am) midnight, or more formal and exact would be 00:30; The practice of adding “dark” and “thirty” (30) can be used sometimes as a slang term in place of an otherwise specific time a time of night, meaning some time when it is dark out between 00:01 - 05:00 hours local time.

Synonym of oh dark thirty

(figuratively) A reward for betrayal.

(historical) A conflict fought largely within the Holy Roman Empire from 1618 to 1648.