year-end sales battle; year-end shopping season
Refers to the intense competition among retailers during the year-end shopping period, typically from late November through December.
When the year-end sales battle begins, every store offers deep discounts.
Online sales grew even more during this year's year-end shopping season.
年末セール refers specifically to year-end sales events, while 年末商戦 emphasizes the competitive aspect among businesses.
年末年始 covers the New Year holiday period, whereas 年末商戦 focuses on the commercial activity leading up to it.
Compound of 年末 (year-end) and 商戦 (sales competition). The term 商戦 itself is a relatively modern coinage reflecting commercial rivalry.