expression
before the end of this year
A set phrase meaning 'by the end of this year' or 'before the year is out'. Used in deadlines, plans, and seasonal greetings.
年末までにこのプロジェクトを終わらせなければならない。
We must finish this project before the end of the year.
年末までお体に気をつけてお過ごしください。
Please take care of yourself until the end of the year.
年末 is a noun meaning 'year-end'; 年末まで adds the particle まで to express 'until the end of the year' or 'by the end of the year'.
Compound of 年末 (year-end) + まで (until). A straightforward temporal expression.