How to say "duration" in Japanese

• 存続そんぞくJLPT N1approx.Common
  noun, suru verb, transitive verb, intransitive verbSeldom the word for duration as a length of time; it means the continuance, survival, or persistence of something — the fact of a thing or state continuing to exist.
  その地方ちほうではその古ふるい風俗ふうぞくがなお存続そんぞくしている。↗

  The old custom is still kept up in that district.
• 間あいだJLPT N4approx.Common
  noun, adverbCovers duration as a period of time — the stretch during which something happens or the interval between events; close to English 'while' and 'during'.
  彼かれは病気びょうきの間あいだすごい勇気ゆうきを示しめした。↗

  He showed great courage during his illness.

Choose 間 for duration as a period of time — the stretch during which something happens or between events; 存続 is really about continuance or survival, so it suits 'duration' only in the sense of something persisting.

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

• 存続そんぞくcontinuance
• デュレイションduration
• 継続時間けいぞくじかんduration
• 持続時間じぞくじかんduration
• 間あいだperiod of time (during, while)
• 作用角さよかく(camshaft) duration