一昨日

Compound of 一昨 (issaku-, “the previous... before...”) +‎ 日 (jitsu, “day”).^[1]

First cited to a text from 1275.^[2]

• (Tokyo) いっさくじつ (Nakadaka – )^[1][3]
• IPA^(key):

一(いっ)昨(さく)日(じつ) • (issakujitsu) 

1. (formal) the day before yesterday, two days ago

• 一昨昨(いっさくさく)日(じつ) (issakusakujitsu, “three days ago”)

/wotot͡sufi/ → /wototofi/ → /wototowi/ → /ototoi/

First cited to a text from roughly 953.^[2]

Shift from Old Japanese ototsui (see Etymology 3 below).^[1][4][2]

The kanji spelling is from issakujitsu (see Etymology 1 above).

• (Tokyo) おととい (Nakadaka – )^[1][3]
• IPA^(key):

一昨(おとと)日(い) • (ototoi) ^{←をととひ (wototofi)?}

1. the day before yesterday, two days ago
   • c. 951–953, Gosen Wakashū (book 14, introduction to poem 872)

     かくてつかはしたりければ、千(ち)里(さと)見(み)侍(はべ)りて、まことにをととひなんかへりまうてこしかど、心地(ここち)のなやましくてなむありつる、とはかりいひをくりてはべりければ、かさねてつかはしける

     Kakute tsukawashi-tarikereba, Chisato mihaberite, makoto ni ototoi nan kaeri mōte koshikado, kokochi no nayamashikutenan aritsuru, towakari ii okurite haberikereba, kasanete tsukawashikeru.

     (please add an English translation of this example)

Usually spelled in kana alone, rarely written with this kanji spelling.

• 一昨日(おととい)御(お)出(い)で (ototoi oide, “go away and don't ever come back”, literally “come here the day before yesterday”)
• 一昨日(おととい)来(こ)い (ototoi koi, “go away and don't ever come back”)
• 一昨昨日(さきおととい) (saki-ototoi, “three days ago”)

⟨woto₂ tu pi₁⟩ → */wotətupʲi/ → /wotot͡sufi/ → /otot͡suwi/ → /otot͡sui/

First attested in the Man'yōshū (c. 759 CE).

Originally a compound of 遠 (oto, “distant, distant past”) +‎ つ (tsu, Old Japanese case-marker particle) +‎ 日 (hi, “day”).^[1][4][2]

The kanji spelling is from issakujitsu (see Etymology 1 above).

• (Tokyo) おとつい (Nakadaka – )^[1][3]
• IPA^(key):

一昨(おとつ)日(い) • (ototsui) ^{←をとつひ (wototufi)?}

1. the day before yesterday, two days ago

Usually spelled in kana alone, rarely written with this kanji spelling.

• 一昨昨日(さきおとつい) (saki-ototsui, “three days ago”)

Compound of 遠 (woto₂, “distant past”) +‎ つ (tu, case-marker particle) +‎ 日 (pi₁, “day”).

一昨日 (woto₂tupi₁) (kana をとつひ)

1. the day before yesterday, two days ago
   • c. 759, Man’yōshū, book 17, poem 3924:

     山乃可比曾許登母見延受乎登都日毛昨日毛今日毛由吉能布禮禮婆

     yama no₂ kapi₁ so₂ko₂ to₂ mo mi₁yezu woto₂tupi₁ mo ki₁no₂pu mo ke₁pu mo yuki₁ no₂ purereba

     (please add an English translation of this quotation)

• Japanese: 一昨日 (ototsui, ototoi)