📅 日期时间Date & Time
时间戳转换Unix Timestamp Converter
Unix 时间戳与日期时间互相转换，支持秒和毫秒，显示本地时间和 UTC。Convert Unix timestamps (seconds/ms) to dates and back, local and UTC.
年龄计算器Age Calculator
根据出生日期精确计算年龄（岁、月、天）、已活天数和距下次生日天数。Calculate exact age in years, months and days, plus days until next birthday.
日期计算器Date Difference Calculator
计算两个日期之间相差多少天、周、月，或计算某日期加减天数后的日期。Days between two dates, or add/subtract days from a date.
时区转换器Time Zone Converter
在北京时间、纽约、伦敦、东京等全球时区之间换算时间，自动处理夏令时。Convert times between world time zones (Beijing, New York, London, Tokyo…) with DST handled.
世界时钟World Clock
实时显示全球主要城市当前时间和时差：北京、纽约、伦敦、东京、悉尼等。Live current time and offsets in major cities worldwide.
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.
工作日计算器Business Days Calculator
计算两个日期之间的工作日天数（排除周末和自定义节假日），或某日期加 N 个工作日。Count working days between dates (excluding weekends and custom holidays), or add N business days.
时间间隔计算器Time Duration Calculator
计算两个时间或日期时间之间相差多少小时、分钟、秒，或时间加减。Calculate the duration between two times or date-times, in hours, minutes and seconds.
闰年判断Leap Year Checker
判断某一年是否为闰年，并列出前后最近的闰年和该年天数、二月天数。Check if a year is a leap year and list nearby leap years.
倒计时（距离某日还有几天）Countdown to Date
倒计时到任意日期时间：距离春节、高考、生日、考试还有多少天、小时、分钟、秒。Countdown to any date/time: days, hours, minutes and seconds remaining.
在线秒表Online Stopwatch
在线秒表计时器，精确到百分之一秒，支持计次（分段）记录。Online stopwatch with 1/100 s precision and lap times.
在线计时器（倒计时提醒）Online Countdown Timer
设定分钟和秒的在线倒计时器，时间到响铃提醒，可用于学习、做饭、运动。Set a countdown timer in minutes/seconds with an alarm sound when time's up.
番茄钟Pomodoro Timer
在线番茄工作法计时器：25 分钟专注 + 5 分钟休息，每 4 个番茄长休息，带提醒音。Pomodoro timer: 25-min focus, 5-min breaks, long break every 4 — with alerts.
万年历 / 日历生成Printable Calendar Generator
生成任意年份和月份的日历，显示周数和今天，可打印。Generate a printable calendar for any month and year, with week numbers.
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.
工时计算器（考勤表）Timesheet Calculator
按每天的上下班时间和休息时长统计总工时、加班时长和工资。Total work hours, overtime and pay from daily clock-in/out times and breaks.
12/24 小时制转换12-Hour ↔ 24-Hour Time Converter
批量把 12 小时制时间（2:30 PM）与 24 小时制（14:30）互相转换，自动识别。Convert times between 12-hour (2:30 PM) and 24-hour (14:30) format in bulk, auto-detected.
儒略日转换器Julian Date Converter
公历日期时间（UTC）与儒略日（JD）、简化儒略日（MJD）互相转换，天文计算常用。Convert UTC date/time to Julian Date (JD) and Modified Julian Date (MJD), and back.
日出日落时间计算器Sunrise & Sunset Calculator
根据经纬度和日期计算日出、日落、正午时间、白昼时长和民用晨昏蒙影时间。Sunrise, sunset, solar noon, day length and civil twilight from latitude, longitude and date.
月相查询Moon Phase Calculator
查询任意日期的月相、月龄、月面照明比例，以及下一次满月和新月的大致时间。Moon phase, age and illumination for any date, with the next full and new moon.
Excel 日期序号转换Excel Date Serial Converter
Excel/WPS 日期序列号（如 46023）与日期互相转换，支持 1900 和 1904 日期系统及时间小数。Convert Excel/Sheets date serial numbers (e.g. 46023) to dates and back, 1900 or 1904 system.
日期格式转换Date Format Converter
把一个日期时间转换为 ISO 8601、RFC 2822、Unix 时间戳、中文、美式、欧式等多种格式。Show a date-time in ISO 8601, RFC 2822, Unix timestamp, Chinese, US, European and other formats.
世界主要节日查询World Holidays
世界主要节日查询：按日期排列的固定节日和中国传统节日，含日期和简介，可搜索。Reference of major world holidays (fixed-date and Chinese traditional), with dates and notes, searchable.
历史上的今天Today in History
查询某一天历史上发生的重大事件（精选、经核实的著名事件），默认显示今天。Look up well-known historical events that happened on a given day of the year (a verified selection); defaults to today.
纪念日计算器（结婚/恋爱周年）Anniversary Calculator
输入结婚、恋爱或任何纪念日的日期，计算已经在一起多少年、月、天，下一个周年纪念日是哪天、还有几天，以及第 100 天、1000 天等特别纪念日，并给出西方传统的周年礼物。Enter a wedding, relationship or any special date to see how many years, months and days it has been, when the next anniversary falls and how many days away it is, the 100th and 1,000th day milestones, and the traditional anniversary gift.
时间转十进制（小时/分钟）Time to Decimal Converter
把时:分:秒（如 2:45:30 或 2h 45m）转换成十进制小时、十进制分钟和总秒数，常用于工时表和计费；也能把 2.75 小时反向换成 2 小时 45 分。Convert hours:minutes:seconds such as 2:45:30 or 2h 45m to decimal hours, decimal minutes and total seconds for timesheets and billing — or turn 2.75 hours back into 2 h 45 min.
罗马数字日期转换器Roman Numeral Date Converter
把日期转换成罗马数字（如纹身、婚礼请柬常用的 V·XX·MMXX），可选月-日-年、日-月-年或年-月-日顺序和分隔符；也能把罗马数字日期还原为普通日期。Turn a date into Roman numerals — like V·XX·MMXX for tattoos and wedding invitations — in month-day-year, day-month-year or year-month-day order with your choice of separator, or decode a Roman numeral date back to a normal date.
倒计时计算器（距离目标日还有多少天、周、工作日、时分）Time Until Calculator (Days, Weeks, Workdays and Hours Until a Date)
计算从今天（或指定起始日）到目标日期还有多少时间：总天数、几周几天、几个月几天、工作日数（周一至周五）、周末天数，以及总小时、分钟数。可选择包含目标当天。目标已过时显示已过去多久。本地处理。Works out how long it is from today (or a start date) to a target date: total days, weeks and days, months and days, workdays (Monday to Friday), weekend days, and total hours and minutes. Optionally count the target day itself. If the date has passed, it shows how long ago it was. Processed locally.
周数计算器（日期加减周数、两个日期相隔几周）Week Calculator (Add or Subtract Weeks, Weeks Between Dates)
在某个日期上加或减若干周（可再加零头天数），或算出两个日期之间相隔几周几天；结果给出星期几和 ISO 周数。起始日默认是今天（按你设备的日期）。本地处理。Add or subtract weeks (plus extra days) from a date, or find how many weeks and days lie between two dates. Results show the weekday and ISO week number. The start date defaults to today (your device's date). Processed locally.
几周前是哪天（以及几周后）Weeks Ago Calculator (and Weeks From Now)
算出某个日期（默认今天）往前或往后若干周（可加零头天数）是哪一天，给出日期、星期几和相隔天数。本地处理。Find the date a number of weeks (plus extra days) before or after a reference date (today by default), with the weekday and the number of days. Processed locally.
其他行星年龄示意Age on Other Planets
地球年龄 * (地球公转日 / 行星公转日)。本地处理。可设置「地球年龄（年）」、「行星」。Earth age * (Earth year days / planet year days). Processed locally. Settings: Age on Earth (years), Planet.
时间加分钟计算器Add Minutes Calculator
在日期时间上加或减整数分钟（可为负），按浏览器本地时区解析与显示。本地处理。Add or subtract a whole number of minutes (may be negative) from a date-time, using the browser local zone. Processed locally.
由年龄推出生年示意Date of Birth from Age (Demo)
用参考日与整数周岁估算出生年与同月日示意生日。未判断今年是否已过生日，仅示意。本地处理。Estimate birth year and a same-month-day demo DOB from a reference date and whole years of age. Does not check whether the birthday has passed — demo only. Processed locally.
小数小时转时分秒Decimal Hours to h:mm:ss
把非负小数小时换成 h:mm:ss（四舍五入到秒）并给出总秒数。本地处理。可设置「小数小时」。Convert non-negative decimal hours to h:mm:ss (rounded to the nearest second) and total seconds. Processed locally. Settings: Decimal hours.
两日期间天数Number of Days Between Dates
计算两个日历日之间的整天数。本地处理。可设置「起始日」、「结束日」。Whole days between two calendar dates. Processed locally. Settings: Start date, End date.
两日期间时长Time Between Dates
给出天数、周数与年数示意。本地处理。可设置「起始日」、「结束日」。Days, weeks and years between two dates. Processed locally. Settings: Start date, End date.
日期加减天数Add Days to a Date
在给定日期上加（或减）整天数；天数留空视为 0。本地处理。可设置「日期」、「天数（可负）」。Add (or subtract) whole days from a date; leave days blank for 0. Processed locally. Settings: Date, Days (may be negative).
时间占比Time Percentage
占比 = 部分时长 / 总时长 × 100%。本地处理。可设置「部分（小时）」、「总计（小时）」。Percent = part duration / total × 100%. Processed locally. Settings: Part (hours), Total (hours).
距秋天还有几天Days Until Fall
按北半球天文秋季（约 9 月 22 日）计算距参考日（默认今天）的天数（示意）。本地处理。Days until astronomical autumn in the northern hemisphere (~22 Sep) from the reference date (defaults to today) (demo). Processed locally.
倒计时天数Countdown Days
距目标日的整天数（可负表示已过）；起始日留空则用今天。本地处理。可设置「目标日」、「起始日（空=今天）」。Whole days until a target date (negative if past); blank start uses today. Processed locally. Settings: Target date, From (blank = today).
在线闹钟Online Alarm Clock
在浏览器里设置闹钟：选择时间和铃声，到点响铃并闪烁标题，支持贪睡、多个闹钟、倒计时显示，设置会保存在本机。适合午休、做饭和学习提醒。Set alarms in your browser: pick a time and a sound, and it rings and flashes the tab title when due — with snooze, multiple alarms and a live countdown. Alarms are saved on this device. Good for naps, cooking and study breaks.
退休倒计时Retirement Countdown
按出生日期和计划退休年龄算出退休日期，以及距今还有多少年、月、天和工作日（周一至周五，未扣除节假日）。本地处理。From your date of birth and planned retirement age, get the retirement date and how many years, months, days and weekdays (Mon-Fri, holidays not excluded) remain. Processed locally.
12 小时制转 24 小时制Convert 12-hour to 24-hour
2:30 PM → 14:30。2:30 PM → 14:30.
24 小时制转 12 小时制Convert 24-hour to 12-hour
14:30 → 2:30 PM。14:30 → 2:30 PM.
查找黑色星期五Find Friday the 13th
列出指定年份所有星期五且为 13 日的日期。可设置「年份」。List every Friday the 13th in a year. Settings: Year.
查找 7 月 4 日星期Find July 4th Weekday
查询某年 7 月 4 日是星期几。可设置「年份」。Weekday of July 4 in a year. Settings: Year.
距离某天还有几天Days Until Calculator
算出从今天（或指定日期）到目标日期还有多少天，并换算成几周几天、几个月几天、工作日（周一至周五）和周末天数；目标已过去时显示已经过去多少天。Count the days from today (or a date you choose) to a target date, as weeks and days, months and days, weekdays (Monday–Friday) and weekend days — or how long ago it was if the date has passed.
半岁生日计算器Half Birthday Calculator
根据出生日期算出半岁生日（生日加 6 个月）是哪一天、下一个半岁生日的日期、还有多少天，以及届时是几岁半；8 月 31 日这类日期会落到 2 月最后一天。Find your half birthday (birthday plus 6 months), the date of the next one, how many days away it is and the age you will be — dates like August 31 fall on the last day of February.
韩国年龄计算器Korean Age Calculator
输入出生日期，算出韩国传统的「虚岁」（出生即 1 岁、每年 1 月 1 日加一岁）、「年龄」（当年年份 − 出生年份）和国际通用的满岁年龄。韩国自 2023 年 6 月 28 日起在法律和行政上统一使用满岁。Enter a date of birth to get the traditional Korean age (1 at birth, plus one every January 1), the year age (current year − birth year) and the international age. Since June 28, 2023, South Korea uses the international age in law and administration.
元旦是星期几（按年份查询）New Year's Day Finder
列出一段年份里每年 1 月 1 日（元旦）是星期几，并统计各星期几出现的次数；也可以只列出元旦落在某个星期几的年份，例如找出元旦是星期五的年份。List the weekday of January 1 (New Year's Day) for every year in a range, with a count per weekday — or list only the years when it falls on a chosen day, such as a Friday.
徒步时间估算Hiking Time Calculator
按距离、累计爬升和下降估算徒步用时：奈史密斯规则（5 km/h + 每爬升 600 m 加 1 小时）、加朗缪尔下坡修正，或德国/瑞士常用的 DIN 33466 方法；可加休息时间。Estimate hiking time from distance, total ascent and descent with Naismith's rule (5 km/h plus 1 hour per 600 m of ascent), with Langmuir's descent corrections, or with the DIN 33466 method used in Germany and Switzerland — plus rest stops.
有声书倍速时长计算器Audiobook Speed Calculator
输入有声书或播客的时长和播放倍速，算出实际收听时间和节省的时间；也可以反过来求在规定时间内听完所需的倍速，或按每天收听时长算出几天能听完。Enter an audiobook or podcast length and playback speed to see the actual listening time and time saved — or find the speed needed to finish in a set time, or how many days it takes at so many minutes a day.
给日历日期加点模糊Add Fuzziness to Calendar Dates
给每行日期随机加减几天（可设范围与种子），用于脱敏或测试。本地处理。可设置「范围（天）」、「种子」。Add or subtract a random number of days from each date (range + seed). Handy for anonymising or tests. Processed locally. Settings: Range (days), Seed.
给时钟时间加点模糊Add Fuzziness to Clock Times
给每行时间随机加减若干秒（可设范围与种子）。本地处理。可设置「范围（秒）」、「种子」。Add or subtract a random number of seconds from each time (range + seed). Processed locally. Settings: Range (seconds), Seed.
分析日历日期Analyze Calendar Date
给出星期、年积日、当季、是否闰年、儒略日等。本地处理。Weekday, day of year, quarter, leap year, Julian day number and more. Processed locally.
分析时钟时间Analyze Clock Time
给出 12 小时制、距午夜秒数、时针分针夹角等。本地处理。12-hour form, seconds since midnight, hour/minute hand angle and more. Processed locally.
计算平均日历日期Calculate Average Calendar Date
对多行日期取平均（按儒略日），输出最接近的日期。本地处理。Average several dates (by Julian day) and round to the nearest date. Processed locally.
计算钟表指针夹角Calculate Clock Hand Angle
计算时针与分针（可选秒针）之间的较小夹角（度）。本地处理。可设置「指针」。Smaller angle in degrees between the hour and minute hands (optional seconds). Processed locally. Settings: Hands.
计算自午夜起的秒数Calculate Seconds Since Midnight
把 HH:MM:SS 换成从 00:00:00 起的秒数。本地处理。Convert HH:MM:SS to seconds since 00:00:00. Processed locally.
计算距午夜的秒数Calculate Seconds Till Midnight
计算从给定时间到下一个 00:00:00 还有多少秒。本地处理。Seconds from the given time until the next 00:00:00. Processed locally.
检查平年Check Common Year
判断年份是平年还是闰年。本地处理。Check whether a year is a common year (not a leap year). Processed locally.
日期转儒略日Convert Date to Julian Day
把公历日期转换成儒略日编号 JDN。本地处理。可设置「输出」。Convert a Gregorian date to Julian Day Number (JDN). Processed locally. Settings: Output.
公历转儒略历日期Convert Gregorian Date to Julian Date
把公历（格里高利历）日期换成同一天的儒略历日期。本地处理。Convert a Gregorian (civil) date to the Julian-calendar date for the same day. Processed locally.
人类时间转 Unix 时间戳Convert Human Time to Unix Time
把 YYYY-MM-DD HH:MM:SS（UTC，可带小数秒）换成 Unix 秒或毫秒。本地处理。Convert YYYY-MM-DD HH:MM:SS (UTC, fractional seconds allowed) to Unix seconds or milliseconds. Processed locally.
儒略历转公历日期Convert Julian Date to Gregorian Date
把儒略历日期换成同一天的公历（格里高利历）日期。本地处理。Convert a Julian-calendar date to the Gregorian date for the same day. Processed locally.
儒略日转日期Convert Julian Day to Date
把儒略日编号 JDN（整数）或带小数的儒略日 JD 换成公历日期与 UT 时间。本地处理。Convert a Julian Day Number (integer) or a fractional Julian date to a Gregorian date and UT time. Processed locally.
军事时间转常规时间Convert Military Time to Regular Time
把 24 小时制（如 1430 或 14:30）换成 12 小时制 AM/PM。本地处理。Convert 24-hour time (1430 or 14:30) to 12-hour AM/PM. Processed locally.
常规时间转军事时间Convert Regular Time to Military Time
把 12 小时制 AM/PM 换成 24 小时制（HHMM 或 HH:MM）。本地处理。可设置「带冒号」。Convert 12-hour AM/PM to 24-hour (HHMM or HH:MM). Processed locally. Settings: With colon.
秒数转时间Convert Seconds to Time
把秒数换成 HH:MM:SS（小时可超过 24，支持很大的整数）。本地处理。Convert a second count to HH:MM:SS (hours may exceed 24; very large whole numbers supported). Processed locally.
国家之间时间换算Convert Time Between Countries
在各国家/地区的时区之间换算时间（覆盖全部有时区的国家与地区，多时区国家逐个列出，自动处理夏令时）。本地处理。Convert a wall time between countries and regions (every country with a time zone; multi-zone countries list each zone; DST aware). Processed locally.
时区之间时间换算Convert Time Between Timezones
在全部 IANA 时区之间换算墙钟时间（可搜索，自动处理夏令时）。本地处理。可设置「从」、「到」。Convert wall-clock time between all IANA time zones (searchable list, DST aware). Processed locally. Settings: From, To.
时间转秒数Convert Time to Seconds
把 HH:MM:SS（或 MM:SS）换成总秒数，小时可以很大，结果精确。本地处理。Convert HH:MM:SS (or MM:SS) to total seconds; hours can be very large and the result is exact. Processed locally.
Unix 时间戳转人类时间Convert Unix Time to Human Time
把 Unix 秒或毫秒换成 UTC 的 YYYY-MM-DD HH:MM:SS。本地处理。可设置「单位」。Convert Unix seconds or milliseconds to UTC YYYY-MM-DD HH:MM:SS. Processed locally. Settings: Unit.
递减日历日期Decrement Calendar Date
把每行日期减去若干天、月或年（可批量，月末自动对齐）。本地处理。可设置「数量」、「单位」。Subtract days, months or years from each date (batch; month ends are clamped). Processed locally. Settings: Amount, Unit.
递减时钟时间Decrement Clock Time
把每行时间减去若干秒（可批量，按日回绕）。本地处理。可设置「秒数」。Subtract seconds from each time (batch; wraps within a day). Processed locally. Settings: Seconds.
绘制月历Draw Monthly Calendar
把指定年月（0001–9999 年）的月历画成图片并下载，可选周一或周日开始。本地完成。Draw a month calendar (years 0001 to 9999) as an image for download, starting weeks on Monday or Sunday. Runs locally.
绘制人生周历（Memento Mori）Draw Memento Mori Calendar
按出生日期绘制人生周格图（默认 90 年），已度过的周与未来周用不同颜色。本地完成。Draw a life-in-weeks grid from a birth date (default 90 years), with lived and future weeks in different colours. Runs locally.
查找圣诞节Find Christmas Day
给出某年圣诞节（12 月 25 日）的日期与星期。本地处理。Christmas Day (25 December) and its weekday for a given year. Processed locally.
按年积日查日期Find Date by Day of Year
输入年份与年积日（1-365/366），得到对应日期。本地处理。From a year and day-of-year (1-365/366), get the calendar date. Processed locally.
查找复活节日期Find Easter Dates
计算某年复活节星期日：西方（公历算法）或东正教（儒略历算法，结果换成公历）。本地处理。Easter Sunday for a year: Western (Gregorian computus) or Orthodox (Julian computus, shown as a Gregorian date). Processed locally.
按日期查季节Find Season by Date
按气象季节（北半球：春 3-5、夏 6-8、秋 9-11、冬 12-2）判断。本地处理。可设置「半球」。Meteorological season (NH: spring Mar-May, summer Jun-Aug, autumn Sep-Nov, winter Dec-Feb). Processed locally. Settings: Hemisphere.
查找特定星期几Find Specific Day
查找某年某月第 n 个星期几（或最后一个）。例如 2024 年 11 月第 4 个星期四。输入：年 月 n 星期(0=日..6=六)，n 为 1-5 或 last（-1）。本地处理。Find the n-th weekday of a month (or the last one), such as the 4th Thursday of Nov 2024. Input: year month n weekday (0=Sun..6=Sat); n is 1-5 or last (-1). Processed locally.
查找感恩节Find Thanksgiving Day
感恩节日期：美国为 11 月第四个星期四，加拿大为 10 月第二个星期一。本地处理。可设置「国家」。Thanksgiving: the 4th Thursday of November in the US or the 2nd Monday of October in Canada. Processed locally. Settings: Country.
按日期查星座Find Zodiac Sign by Date
按常用热带黄道日期划分查星座。本地处理。Tropical zodiac sign from the usual date ranges. Processed locally.
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.
格式化时钟时间Format Clock Time
把 HH:MM:SS 格式化成 24h / 12h 等多种写法。本地处理。Format HH:MM:SS into 24h / 12h writings. Processed locally.
生成自定义日历日期序列Generate Custom Calendar Dates
从起始日期起每隔 n 天、周、月或年生成 k 个日期（最多到 9999-12-31）。本地处理。可设置「间隔」、「单位」、「个数」。From a start date, emit k dates every n days, weeks, months or years (up to 9999-12-31). Processed locally. Settings: Step, Unit, Count.
生成自定义时钟时间序列Generate Custom Clock Times
从起始时间起每隔 n 秒生成 k 个时间（按日回绕）。本地处理。可设置「间隔秒」、「个数」。From a start time, emit k times every n seconds (wraps within a day). Processed locally. Settings: Step seconds, Count.
生成日期序列Generate Date Sequence
生成从起始到结束（含两端）的日期列表，可按天、周、月或年步进，结束早于开始时倒序生成。输入两行：起、止。本地处理。Dates from start to end (inclusive), stepping by days, weeks, months or years; an end before the start gives a descending list. Input two lines: start, end. Processed locally.
生成奇妙日历日期Generate Magic Calendar Dates
列出某年中“月=日”的日期（如 01-01、02-02…）。本地处理。List dates in a year where month equals day (01-01, 02-02, …). Processed locally.
生成奇妙时钟时间Generate Magic Clock Times
列出 HH:HH:HH 形式的对称时间（00:00:00 … 23:23:23 中合法者）。本地处理。List symmetric HH:HH:HH times that are valid (00:00:00 …). Processed locally.
生成回文日历日期Generate Palindromic Calendar Dates
列出某年中 YYYYMMDD 为回文的日期。本地处理。List dates in a year whose YYYYMMDD digits are a palindrome. Processed locally.
生成回文时钟时间Generate Palindromic Clock Times
列出 HH:MM 读作回文的时间（如 12:21）。本地处理。List HH:MM times that read as palindromes (e.g. 12:21). Processed locally.
生成随机日历日期Generate Random Calendar Dates
在起止日期之间随机生成若干日期（可设种子）。输入两行起止。本地处理。可设置「个数」、「种子」。Random dates between start and end (optional seed). Two lines: start, end. Processed locally. Settings: Count, Seed.
生成随机时钟时间Generate Random Clock Times
随机生成若干 HH:MM:SS（可设种子）。本地处理。可设置「个数」、「种子」。Random HH:MM:SS times (optional seed). Processed locally. Settings: Count, Seed.
生成随机 Unix 时间戳Generate Random Unix Time
在给定秒级范围内随机生成 Unix 时间戳。输入两行：最小、最大（秒）。本地处理。可设置「个数」、「种子」。Random Unix timestamps in a second range. Two lines: min, max. Processed locally. Settings: Count, Seed.
生成时间序列Generate Time Sequence
从起始到结束（含）按固定秒步长生成时间，结束早于开始时跨过午夜。输入两行起止时间，选项为步长秒。本地处理。Times from start to end (inclusive) with a fixed step in seconds; an end before the start crosses midnight. Two lines + step. Processed locally.
生成 Unix 时间戳序列Generate Unix Time Sequence
从起始到结束按步长生成 Unix 秒序列（结束小于起始时倒序）。输入两行起止，选项为步长。本地处理。可设置「步长」。Unix second sequence from start to end with a step (descending when the end is smaller). Processed locally. Settings: Step.
递增日历日期Increment Calendar Date
把每行日期加上若干天、月或年（可批量，月末自动对齐，最多到 9999-12-31）。本地处理。可设置「数量」、「单位」。Add days, months or years to each date (batch; month ends are clamped; up to 9999-12-31). Processed locally. Settings: Amount, Unit.
递增时钟时间Increment Clock Time
把每行时间加上若干秒（可批量，按日回绕并提示跨日）。本地处理。可设置「秒数」。Add seconds to each time (batch; wraps within a day with a next-day note). Processed locally. Settings: Seconds.
镜像时钟时间Mirror Clock Time
把时间映射到“钟面镜像”（12 小时对称，如 2:00 ↔ 10:00），可批量。本地处理。Map times to their clock-face mirror (12-hour symmetry, e.g. 2:00 ↔ 10:00), one per line. Processed locally.
列出全部星座Print All Zodiac Signs
列出十二星座及常用日期范围。本地处理。List the twelve zodiac signs with usual date ranges. Processed locally.
四舍五入日历日期Round Calendar Date
按周/月/年对齐日期（向下、最近或向上）。本地处理。可设置「单位」、「方式」。Align a date to week/month/year (down, nearest or up). Processed locally. Settings: Unit, Mode.
四舍五入时钟时间Round Clock Time
把时间四舍五入到最近的 n 分钟。本地处理。可设置「分钟」。Round a time to the nearest n minutes. Processed locally. Settings: Minutes.
按夹角反推时钟时间Set Clock Hand Angle
给定时针与分针的夹角（0-180°），列出一天中夹角正好相等的整分时刻（可设容差）。本地处理。Given an hour-minute hand angle (0-180°), list the whole-minute times in a day whose angle matches exactly (optional tolerance). Processed locally.
排序日历日期Sort Calendar Dates
按时间先后排序每行日期，无效的行单独列出。本地处理。可设置「降序」。Sort dates one per line in chronological order; invalid lines are listed separately. Processed locally. Settings: Descending.
排序时钟时间Sort Clock Times
按一天内先后排序每行时间，无效的行单独列出。本地处理。可设置「降序」。Sort times one per line within a day; invalid lines are listed separately. Processed locally. Settings: Descending.
排序日期区间Sort Date Intervals
每行一个区间“起始 结束”，按开始日期排序，开始相同再按结束日期，仍相同保持原顺序。无效的行带行号列出。本地处理。Sort date intervals (start end per line) by start date, then end date, then input order. Invalid lines are listed with line numbers. Processed locally.
排序时间区间Sort Time Intervals
每行一个区间“起始 结束”，按开始时间排序，开始相同再按结束时间，仍相同保持原顺序；可跨午夜。本地处理。Sort time intervals by start time, then end time, then input order; overnight intervals are allowed. Processed locally.
拼读日历日期Spell Calendar Date
把日期写成中文大写读法（如 二〇二六年十月二十日 星期二）或英文读法。本地处理。Spell a date out in words in English (e.g. Tuesday, October twentieth, twenty twenty-six) or Chinese. Processed locally.
拼读时钟时间Spell Clock Time
把时间写成中文读法（如 下午一点零五分）或英文口语（如 one oh five PM）。本地处理。Spell a time in words in English (e.g. one oh five PM) or Chinese. Processed locally.
把日期范围切成区间Split Date into Intervals
第一行开始日期、第二行结束日期，按每段天数切成多段（含两端，最多 500 段）。本地处理。Split a date range (start on line 1, end on line 2, both included) into chunks of n days, up to 500 chunks. Processed locally.
把时间范围切成区间Split Time into Intervals
第一行开始时间、第二行结束时间，按每段秒数切成多段（最多 500 段，可跨午夜）。本地处理。Split a time range (start on line 1, end on line 2) into chunks of n seconds, up to 500 chunks; overnight ranges are allowed. Processed locally.
截断日历日期Truncate Calendar Date
把每行日期截到所在周（周一或周日开始）、月、季度或年的第一天。本地处理。可设置「截断到」。Truncate each date (one per line) to the start of its week (Monday or Sunday), month, quarter or year. Processed locally. Settings: Truncate to.
截断时钟时间Truncate Clock Time
把每行时间向下截到整分、5/10/15/30 分钟或整点。本地处理。可设置「截断到」。Truncate each time (one per line) down to the minute, 5, 10, 15 or 30 minutes, or the hour. Processed locally. Settings: Truncate to.
校验日历日期Validate Calendar Date
逐行检查是否为有效的公历日期 YYYY-MM-DD（0001–9999 年），每行给出结论和原因。本地处理。Check line by line whether each entry is a valid Gregorian YYYY-MM-DD date (years 0001–9999), with a verdict and reason per line. Processed locally.
校验时钟时间Validate Clock Time
逐行检查是否为有效的 24 小时制时间 HH:MM 或 HH:MM:SS，每行给出结论和原因。本地处理。Check line by line whether each entry is a valid 24-hour HH:MM or HH:MM:SS time, with a verdict and reason per line. Processed locally.
可视化日期区间Visualize Date Intervals
把每行“起始 结束”日期区间画成甘特图（按开始日期定位、长度按天数），带日期刻度和图例，可下载 SVG/PNG，最多 200 个。本地处理。Draw date intervals (start end per line) as a Gantt chart positioned by start date with length proportional to days, a date axis and a legend; download as SVG or PNG; up to 200 items. Processed locally.
可视化时间区间Visualize Time Intervals
把每行“起始 结束”时间区间画成甘特图（按开始时间定位、长度按时长，可跨午夜），带时刻刻度和图例，可下载 SVG/PNG，最多 200 个。本地处理。Draw time intervals (start end per line) as a Gantt chart positioned by start time with length proportional to duration (overnight allowed), a time axis and a legend; download as SVG or PNG; up to 200 items. Processed locally.
日期时间差Date/Time Difference
计算两个日期时间之间的天数、小时与分钟差。本地处理。可设置「开始」、「结束」。Difference in days, hours and minutes between two date-times. Processed locally. Settings: Start, End.
日期时间计算器Date/Time Calculator
在某个日期时间上加减天 / 小时 / 分钟。本地处理。Add or subtract days, hours and minutes from a date-time. Processed locally.
支票日期大写Check Date in Chinese Words
按中国人民银行《支付结算办法》的票据填写规定，把出票日期写成中文大写（月为壹、贰、壹拾和日为壹至玖、壹拾、贰拾、叁拾时前加“零”，日为拾壹至拾玖时前加“壹”）。本地处理。Writes a cheque issue date in Chinese capital numerals following the People's Bank of China payment-settlement rules (a leading ling (zero) for months 1, 2 and 10 and for days 1–9, 10, 20 and 30; a leading yi (one) for days 11–19). Processed locally.
今天的日期（实时时钟、第几天、ISO 周）Today's Date (live clock, day of year, ISO week)
实时显示今天的日期和时间（本地时区）：多种日期格式、星期、今年第几天、ISO 周数、今年还剩几天和 Unix 时间戳。本地处理。Today's date and a live clock in your local time zone: several date formats, weekday, day of the year, ISO week number, days left in the year and the Unix timestamp. Processed locally.
交货周期与再订货点Lead Time & Reorder Point Calculator
两种模式：按下单日和收货日计算交货周期（日历日或工作日，跳过周六日），或按再订货点 = 日均需求 × 交货周期 + 安全库存计算何时补货。日期会严格校验（如 2026-02-30 无效）。本地处理。Two modes: lead time from the order and receive dates (calendar days or business days, skipping weekends), or the reorder point = daily demand × lead time + safety stock. Dates are validated strictly (2026-02-30 is rejected). Processed locally.
出生年份计算器（按年龄和是否已过生日）Birth Year Calculator (from Age and Birthday)
由当前年龄和今年是否已过生日算出生年份；不确定是否已过生日时给出两个可能的年份。参考年份默认是今年，也可以改成任意年份。本地处理。Find the birth year from a current age and whether the birthday has passed this year; if you are not sure, both possible years are given. The reference year defaults to this year and can be changed. Processed locally.
经过时间计算器（时:分:秒、跨午夜、扣休息）Elapsed Time Calculator (h:mm:ss, Overnight, Breaks)
输入开始和结束时间（24 小时制或 AM/PM，可带秒）算经过的时间，结束早于开始时按跨午夜处理，可扣除休息分钟数，同时给出小时小数和总分钟数，方便算工时。本地处理。Enter start and end times (24-hour or AM/PM, seconds optional) to get the elapsed time. An end before the start counts as overnight, break minutes can be subtracted, and the result is also shown in decimal hours and total minutes for timesheets. Processed locally.
今年还剩多少天（含工作日、周数、进度）Days Left in the Year (with Weekdays, Weeks, Progress)
从所选日期（留空为今天）到当年 12 月 31 日还剩多少天，可选是否把当天算进去；同时给出剩余周数、剩余工作日（周一至周五，不含节假日）、已过天数和全年进度百分比。本地处理。See how many days are left from a date (blank for today) to 31 December of that year, with or without counting that day, plus the weeks left, weekdays left (Monday to Friday, holidays not removed), days passed and the share of the year gone. Processed locally.