Several parts combine into one character.

Compound character: a person (亻) beside a moon (月) or stars. The encoded definition is gentler than English "night" — not "deep darkness" but "the time when a person stands under the moon". The poetic angle: ancient scribes defined night by lunar companionship rather than absence of light. Identical across 繁體 / 新字体 / 简体. Pairs with 昼 (daytime) as the day/night opposition.

Mandarin: yè, falling 4th tone. 夜 in modern Mandarin feels slightly literary — the everyday word for "night" leans toward 晚上 (wǎnshang). But 夜 dominates compound vocabulary: 夜晚 (yèwǎn, night), 夜里 (yèli, in the night), 夜班 (yèbān, night shift), 熬夜 (áoyè, to stay up late / pull an all-nighter), 半夜 (bànyè, midnight), 黑夜 (hēiyè, dark night), 夜市 (yèshì, night market — a Taiwanese cultural institution).

Japanese: on-reading ヤ (ya) for compounds — 夜間 (yakan, nighttime — formal), 徹夜 (tetsuya, all-nighter / staying up all night — important student/work vocabulary), 深夜 (shin'ya, deep night / late night), 夜中 (yonaka, middle of the night — irregular reading: kun + on hybrid), 夜行 (yakō, night-flying / night-traveling — used for night trains and night buses). Kun-readings: よる (yoru) and よ (yo) — 夜 (yoru, night), 月夜 (tsukiyo, moonlit night).

The Japanese keyword 徹夜 (tetsuya, "all-nighter") is essential cultural vocabulary — Japanese students and workers regularly 徹夜 to finish reports or study, dramatized in countless dramas and anime.

Memory aid: a person standing beside the moon — night defined by lunar companionship.