duration; length of time
Refers to the period during which something continues or lasts. Used in technical, formal, and everyday contexts.
The duration of this medicine is about 8 hours.
I set the meeting duration to 30 minutes.
期間 is a general term for a period or interval, while 継続時間 emphasizes the continuous duration of an action or state.
持続時間 is a near-synonym also meaning duration, often used interchangeably, but 継続時間 may slightly emphasize continuation over time.
Compound of 継続 (continuation) and 時間 (time). The exact historical derivation is uncertain, but it follows a common Sino-Japanese word-formation pattern.