📆 星期几查询Day of the Week Calculator
查询任意日期是星期几，以及该日是一年中的第几天、第几周、第几季度、当月天数。Find the weekday of any date, plus day of year, ISO week, quarter and days in month.
使用说明与常见问题How-to & FAQ
「星期几查询」是什么？What is the Day of the Week Calculator tool?
查询任意日期是星期几，以及该日是一年中的第几天、第几周、第几季度、当月天数。Find the weekday of any date, plus day of year, ISO week, quarter and days in month.
如何使用「星期几查询」？How do I use the Day of the Week Calculator tool?
在「星期几查询」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 Day of the Week Calculator: Fill in "Date"; results are recalculated instantly as you type.
和时区有关吗？Do time zones matter?
无关。「星期几查询」把你选择的日期当作纯日历日期（按 UTC）计算星期、周数和季度，不读取设备时间，所以时区和夏令时不影响结果。No. The Day of the Week Calculator treats the date you choose as a plain calendar date (computed in UTC) for the weekday, week number and quarter; it never reads the device clock, so time zones and daylight saving time do not affect the result.
「星期几查询」免费吗？需要注册吗？Is the Day of the Week Calculator free? Do I need an account?
「星期几查询」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 Day of the Week 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.