also: いちにちさんしゅう
noun
impatiently waiting; each moment feeling like an eternity
A yojijukugo expressing the feeling that waiting makes time pass unbearably slowly, as if one day feels like three autumns. Used in literary or formal contexts.
彼女からの返事を待つ間は、まさに一日三秋の思いだった。
While waiting for her reply, it truly felt like each moment was an eternity.
Standard kanji form for this yojijukugo. The reading いちにちさんしゅう is also possible but less common.
Alternate reading; いちじつさんしゅう is more typical for this idiom.
Similar meaning: waiting impatiently, with a sense that a single moment feels like a thousand autumns. 一日三秋 emphasizes a whole day feeling like three autumns, while 一刻千秋 intensifies it to a single moment.
From classical Chinese literature, expressing the feeling that waiting makes a single day feel as long as three autumns. The exact historical derivation is uncertain; the kanji spelling is conventionally associated with this meaning.