🧾 格式化日历日期Format Calendar Date
把 YYYY-MM-DD 格式化成多种写法（含 ISO 周），也可用自定义模板。本地处理。Format YYYY-MM-DD into several common writings (including the ISO week), or with your own pattern. Processed locally.
使用说明与常见问题How-to & FAQ
「格式化日历日期」是什么？What is the Format Calendar Date tool?
把 YYYY-MM-DD 格式化成多种写法（含 ISO 周），也可用自定义模板。本地处理。Format YYYY-MM-DD into several common writings (including the ISO week), or with your own pattern. Processed locally.
如何使用「格式化日历日期」？How do I use the Format Calendar Date tool?
输入日期 YYYY-MM-DD，下方列出多种常见写法；也可以在“自定义模板”里写自己的格式，如 GGGG-[W]WW-E。Enter a date as YYYY-MM-DD to see several common formats, or write your own in Custom pattern, such as GGGG-[W]WW-E.
会给出哪些写法？Which formats are shown?
依次给出 ISO（YYYY-MM-DD）、美式（M/D/YYYY）、欧式（DD/MM/YYYY）、带星期的长格式和 ISO 周（如 2026-W43-2）。年份一律 4 位补零。ISO (YYYY-MM-DD), US (M/D/YYYY), European (DD/MM/YYYY), a long form with the weekday, and the ISO week such as 2026-W43-2. Years always have 4 digits.
自定义模板支持哪些记号？Which tokens can a custom pattern use?
YYYY 年，MM/M 月，DD/D 日，MMMM/MMM 英文月名，dddd/ddd 英文星期，DDDD 年积日，GGGG ISO 周年，WW/W ISO 周数，E ISO 星期（1=周一）；方括号里的文字原样输出，如 GGGG-[W]WW-E。YYYY year, MM or M month, DD or D day, MMMM or MMM month name, dddd or ddd weekday name, DDDD day of the year, GGGG ISO week-year, WW or W ISO week number and E ISO weekday (1 is Monday). Text in square brackets is kept as is, as in GGGG-[W]WW-E.
ISO 周年为什么可能和年份不同？Why can the ISO week-year differ from the year?
ISO 周从周一开始，包含当年第一个星期四的那一周是第 1 周，所以 2027-01-01 属于 2026-W53，2024-12-30 属于 2025-W01。ISO weeks start on Monday and week 1 is the week with the year's first Thursday, so 2027-01-01 is in 2026-W53 and 2024-12-30 is in 2025-W01.
这个工具和时区有关吗？Do time zones affect this tool?
无关。结果只由输入的年份或日期按历法规则算出，不读取设备时钟，也不使用任何时区。No. The result is worked out from the year or date you enter with calendar rules alone; it never reads your device clock or uses a time zone.
有哪些选项可以调整？What options can I adjust?
「格式化日历日期」的设置：「自定义模板（可选）」可留空。每次生成结果都按当前设置处理。Settings in the Format Calendar Date tool — "Custom pattern (optional)" optional. The result always uses the current settings.
「格式化日历日期」免费吗？需要注册吗？Is the Format Calendar Date tool free? Do I need an account?
「格式化日历日期」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Format Calendar Date tool is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.