年月|としつきtoshitsuki[2]nakadaka (mid-high)

1. nounmonths and years
   あれだけのコインを収集しゅうしゅうするのにどれだけの年月としつきがかかりましたか。↗

   How long did it take you to collect so many coins?

• Synonym歳月さいげつWrittenWritten/formal word for the years as they flow by, as in 「歳月人を待たず」; more literary and wistful than 「年月」.
• Synonym月日つきひNeutralEveryday word for time passing, as in 「月日が経つ」; more colloquial than 「年月」, and can also mean a calendar date.
• Synonym日月じつげつWrittenWritten word for the sun and moon, or for the years; rarely used in modern Japanese.
• Related長年ながねんNeutralNeutral word for many years, as in 「長年の夢」; stresses sheer length of time and often works as a modifier.
• Related長期ちょうきNeutralNeutral word for a long-term span, as in 「長期休暇」; purely objective, with none of 「年月」's sense of the years flowing by.
• Related春秋しゅんじゅうWrittenWritten word for the years or for one's age, mostly seen in 「春秋に富む」.
• Related千秋せんしゅうWrittenWritten term for a thousand years, best known from 「一日千秋」.
• Related多年たねんNeutralNeutral word for many years that leans written, as in 「多年の研究」.
• Related積年せきねんWrittenWritten word for years-long accumulation, as in 「積年の恨み」; typically of feelings built up over time.
• Related長い間ながいあいだCasualColloquial phrase for a long time, as in 「長い間お世話になりました」; the natural spoken choice over 「年月」.
• Related千載せんざいWrittenWritten term for a thousand years, kept mostly to the phrase 「千載一遇」.
• Related星霜せいそうWrittenLiterary word for the years, mostly in 「幾星霜」; strongly poetic flavor.
• Related百世ひゃくせいWrittenWritten term for generation after generation, i.e. ages on end; rarely seen in modern Japanese.
• Related長期間ちょうきかんNeutralNeutral word for a very long period, used in objective explanation; no feel of passing years.
• Related烏兎うとWrittenArchaic written word for the sun and moon, hence for time's passage; virtually unused today.
• Related長日月ちょうじつげつWrittenWritten word for long months and years; actual usage examples are scarce.
• Related永年えいねんNeutralSame word as above, also written 「永年」; often in 「長年にわたり」 for 'continuing over many years', stressing duration more than 「年月」.
• Related千歳ちとせWrittenSame word as above, also written 「千歳」; archaic written word for a thousand years, i.e. an extremely long time, not normally used alone.

Use 「年月」 for the years and months as they pass. In written prose say 「歳月」; in everyday speech, 「月日」 or 「長い間」. For something continuing over many years use 「長年」, and for an objective long-term span 「長期」. The rest are literary or set-phrase words: 「千載」 and 「千秋」 for a thousand years, 「春秋」 for age, 「積年」 for long-accumulated feelings, 「多年」 for many years, 「星霜」 for a poetic flavor; 「日月」「百世」「烏兎」「長日月」 are rare today, and 「長期間」 is a plain 'long period'.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 年ねんと月つき。時間じかんの流ながれ又または積み重つみかさね。歳月さいげつ。