乙いつ夜や

also: おつや

い

つ

や

Meanings

second watch of the night; around 9pm to 11pm

archaic

Archaic term from the traditional Chinese/Japanese timekeeping system dividing the night into five watches (五夜). 乙夜 is the second watch, roughly corresponding to 9pm–11pm. Not used in modern everyday language; encountered mainly in historical or literary contexts.

古こ典てんでは、乙いつ夜やは夜よるの二に番ばん目めの刻こく限げんとされる。
In classical texts, 乙夜 is considered the second period of the night.

Kanji

乙the latter, duplicate, strange
夜night, evening

Related words

五ご夜や
五夜 refers to the entire system of five night watches, while 乙夜 specifically denotes the second watch.
初しょ夜や
初夜 is the first watch (approx. 7pm–9pm), immediately preceding 乙夜.
丙へい夜や
丙夜 is the third watch (approx. 11pm–1am), following 乙夜.

Written forms

乙夜Usage100%
- いつや
  Archaic term; the reading いつや is the standard on'yomi for this compound.
- おつや
  Alternate reading; おつ is a less common on'yomi for 乙, but appears in some historical contexts.
おつや

Etymology

From the Chinese system of dividing the night into five watches, each associated with one of the ten celestial stems (十干). 乙 is the second stem, hence the second watch. The exact derivation of the readings いつや and おつや is uncertain, but they reflect different on'yomi traditions for 乙.