busy and quiet periods; press and slack of business
Refers to the fluctuation between busy and slow times, especially in business or work contexts. Often used in formal or business writing.
This industry has extreme differences between busy and slow periods.
We adjust staffing according to the busy and slack periods.
Compound of 繁 (はん, 'busy, flourishing') and 閑 (かん, 'quiet, leisure'). The exact historical derivation is uncertain, but the word is used in modern formal contexts.