Refers to the period around the end of the year, especially late December. Often used in contexts like year-end sales, greetings, or preparations.
The year-end big sale has started.
I offer you my year-end greetings.
The year-end sale has started at the department store.
At this year-end season, I wish you all good health.
This year, too, we are finally heading into the year-end period.