一日千秋

Compound of 一日 (ichinichi, “one day”) +‎ 千秋 (senshū, “a thousand autumns”, poetic phrasing for “a thousand years”).[1][2][3][4]

First cited to the late 1870s.[1]

• (Tokyo) いちにちせんしゅう [ìchíníchí séńshúú] (Heiban – [0])[3][5]
• IPA^(key): [it͡ɕiɲ̟it͡ɕi̥ sẽ̞ɰ̃ɕɨᵝː]

• (Tokyo) いちにちせんしゅう [ìchíníchí sèńshúú] (Heiban + Heiban – [0]-[0])[3][5][4]

一(いち)日(にち)千(せん)秋(しゅう) • (ichinichi senshū) ^{←いちにちせんしう (itiniti sensiu)?}

1. [from late 1870s] a strong sense of impatience, that what one hopes for will take forever before it comes to pass: the sense that time has slowed to a crawl

References tend to list ichinichi senshū as the primary reading,[1][2][4] but some list ichijitsu senshū as the primary instead.[3]

An informal survey of usage patterns online suggests that both readings are in current use at roughly similar frequencies.

Compound of 一日 (ichijitsu, “one day”) +‎ 千秋 (senshū, “a thousand autumns”, poetic phrasing for “a thousand years”).[1][2][3][4]

Shift from earlier ichinichi senshū reading, swapping out the goon reading nichi for 日 for the kan'on reading jitsu instead.

First cited to 1897.[1]

• (Tokyo) いちじつせんしゅう [ìchíjítsú séńshúú] (Heiban – [0])[3][5]
• IPA^(key): [it͡ɕiʑit͡sɨ̥ᵝ sẽ̞ɰ̃ɕɨᵝː]

• (Tokyo) いちじつせんしゅう [ìchíjítsú sèńshúú] (Heiban + Heiban – [0]-[0])[3][5]

一(いち)日(じつ)千(せん)秋(しゅう) • (ichijitsu senshū) ^{←いちじつせんしう (itizitu sensiu)?}

1. [from 1897] a strong sense of impatience, that what one hopes for will take forever before it comes to pass: the sense that time has slowed to a crawl

References tend to list ichinichi senshū as the primary reading,[1][2][4] but some list ichijitsu senshū as the primary instead.[3]

An informal survey of usage patterns online suggests that both readings are in current use at roughly similar frequencies.

• 一日三秋 (ichinichi sanshū, ichijitsu sanshū, literally “one day, three autumns”)
• 一刻千秋 (ikkoku senshū, literally “one moment, a thousand autumns”)