夜間|やかんyakan[1]atamadaka (head-high)

1. noun, adverbnight; nighttime
   フクロウは昼間ひるま寝ねていて夜間やかん狩かりをします。↗

   An owl sleeps by day and hunts by night.

• Synonym夜よるNeutralThe everyday word for night, by far the most common in speech; 「夜間」 sounds more formal and turns up mainly in notices and rules, as in 「夜間工事」.
• Related晩ばんNeutralCovers the evening from dusk to bedtime and can also mean dinner; 「夜間」 refers broadly to the night-time period and is more formal.
• Related夜分やぶんWrittenWritten, formal prose for nighttime, typically used to apologize for disturbing someone late, as in 「夜分に失礼します」.
• Antonym昼間ひるまNeutralMeans daytime and is the direct opposite of 「夜間」, as in 「昼間の部」.

Use 「夜間」 for night-time hours in rules and official notices, as in 「夜間診療」. In everyday speech say 「夜」; for the evening or dinner use 「晩」; to apologize for a late-night contact, 「夜分」; for daytime, 「昼間」.

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

1. 夜よるの間あいだ。