上じょう刻こく

noun

first third of a two-hour period

Refers to the first ~40 minutes of a traditional two-hour time block (刻). Used in historical or formal contexts, such as old clock systems or ceremonial schedules.

• 江え戸ど時じ代だいの時じ刻こく制せい度どでは、丑うしの上じょう刻こくは午ご前ぜん1時じから1時じ40分ぷんごろにあたる。

  In the Edo-period time system, the first third of the hour of the Ox corresponds to roughly 1:00 to 1:40 AM.