end-of-year settling of accounts
Refers to the traditional practice of settling financial accounts at the end of the year, especially in business contexts.
The end of the year is busy with settling accounts.
年末 is a general term for the end of the year, while 節季仕舞い specifically refers to the financial settlement process.
決算 is a broader term for settlement of accounts or financial closing, not necessarily tied to the year-end.
Compound of 節季 (せっき, 'end of a season/year') and 仕舞い (しまい, 'finishing, closing'). The exact historical derivation is uncertain, but the term is conventionally associated with year-end account settlement.