The week number obtained after subtracting one week from January 4, 2026 is incorrect.

[datastructurey]

Describe the bug
Subtracting one week from January 4, 2026, gives the week number as the first week of 2025, which is incorrect.

dayjs('2016-01-04').subtract(1, 'w').format('YYYY年w周') // 2025年1周

Expected behavior
The correct answer should be the 53rd week of 2025.

dayjs('2016-01-04').subtract(1, 'w').format('YYYY年w周') // 2015年53周

Information

• Day.js Version 1.11.19
• OS: macOS Sequoia 15.7.2
• Browser chrome 143.0.7499.170
• Time zone: UTC/GMT+08:00（Asia/Shanghai）