🗓️ 周数计算器（第几周）Week Number Calculator
查询任意日期是今年第几周（ISO 周）、第几天、星期几和第几季度。Find the ISO week number, day of year, weekday and quarter for any date.
使用说明与常见问题How-to & FAQ
「周数计算器（第几周）」是什么？What is the Week Number Calculator tool?
查询任意日期是今年第几周（ISO 周）、第几天、星期几和第几季度。Find the ISO week number, day of year, weekday and quarter for any date.
如何使用「周数计算器（第几周）」？How do I use the Week Number Calculator tool?
在「周数计算器（第几周）」中，填写「日期」等参数，结果会随输入实时计算并显示在下方。In the Week Number Calculator: Fill in "Date"; results are recalculated instantly as you type.
时区如何处理？How are time zones handled?
「周数计算器（第几周）」按 UTC（协调世界时）或纯日期计算，不受你设备时区和夏令时影响。The Week Number Calculator works in UTC (or with plain calendar dates), so your device's time zone and daylight saving time do not affect the result.
「周数计算器（第几周）」免费吗？需要注册吗？Is the Week Number Calculator free? Do I need an account?
「周数计算器（第几周）」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 Week Number Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.