📅 日期时间Date & Time （第 2 页）(page 2)
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.