Date & Time Tools

Add Days to Date Online →

Add or subtract days, weeks, months, or years from a date, with month ends handled.

Add Fuzziness to Clock Time Generator →

Add Fuzziness to Clock Time Online - Generate randomized time variations for testing, simulations, and development.

Add Time to Clock Online →

Add or subtract hours, minutes, or seconds from a clock time, wrapping past midnight.

Age Difference Calculator →

Find the exact difference between two dates in years, months, and days, plus total days.

Analyze Calendar Date →

Mathematically analyze calendar date completely. Extract structural leap statuses, ISO week formatting, and specific seasons natively…

Analyze Clock Time →

Mathematically Analyze Clock Time perfectly. Uncover fuzzy phrasing, precise AM/PM calculations, completed percentages, and angles.

Average Date Calculator →

Paste a list of dates and get their average (mean) date, plus the earliest and latest…

Calculate Average Clock Time →

Calculate the average clock time from a list using circular mean - correct across midnight. Free,…

Calculate Clock Hand Angle →

Calculate the angle between clock hands instantly in your browser. Free, offline, client-side - both smaller…

Calculate Date at Percent of Year →

Calculate Date at Percent of Year - Find the calendar date corresponding to any percentage of…

Calculate Seconds Since Midnight →

Calculate Seconds Since Midnight - exact seconds elapsed since midnight for current or custom time. Free,…

Calculate Seconds Till Midnight →

Calculate Seconds Till Midnight and Count the seconds left until midnight for current or custom time.…

Calculate Time Zone Difference →

Calculate Time Zone Difference between any two time zones with DST awareness. Free, offline, client-side -…

Check Common Year →

Check Common Year whether any year from 1 to 999999 is a common 365-day year or…

Check Leap Year →

Check whether a year is a leap year. Gregorian divisibility breakdown + nearest leap years before…

Clock Time Formatter →

Convert a clock time between 24-hour and 12-hour formats, with or without seconds.

Convert 12-Hour to 24-Hour Time →

Convert 12-hour AM/PM time to 24-hour military format - hours, minutes, and optional seconds. Free, client-side,…

Convert 24-Hour to 12-Hour Time →

Convert 24-Hour to 12-Hour AM/PM format - hours, minutes, and optional seconds. Free, client-side, instant, offline,…

Convert Cat Age to Human Years →

Convert Cat Age to Human Years instantly with our free online tool! Understand your cat’s life…

Convert Date to Julian Day →

online date to Julian Day converter. Returns JD, JDN, MJD, and J2000 offset with Julian/Gregorian switch.…

Convert Days to Hours →

online days to hours converter with minute/second/week/year breakdown. Client-side, instant, secure - no uploads.

Convert Days to Months →

online days to months converter with 5 divisor options plus calendar-accurate mode from a start date.…

Convert Days to Weeks →

online days to weeks converter with 7-day calendar or 5-day business-week modes plus day-remainder split. Client-side,…

Convert Days to Years →

online days to years converter with Gregorian / Julian / tropical / common-year divisors plus calendar-exact…

Convert Dog Age to Human Years →

online dog-to-human years calculator using AAHA/AVMA size-based formula. Shows life stage, lifespan estimate, step-by-step math. Client-side.

Convert Gregorian Date to Julian Date →

Convert Gregorian calendar dates to Julian calendar dates with Julian Day Number, day-of-week, and offset. Handles…

Convert Hours to Days →

Convert hours to days with multi-unit breakdown - days, weeks, months, years, minutes, seconds. Free, offline,…

Convert Human Age to Cat Years →

Convert human age to cat years with life-stage classification. AAFP veterinary scale. Free, offline, client-side, instant.

Convert Human Age to Dog Years →

Convert human age to dog years by breed size (Toy/Small/Medium/Large/Giant). AKC life stage. Free, offline, client-side.

Convert Human Time to Unix Time →

Convert dates to Unix timestamps - seconds, ms, μs, ns, FILETIME, ISO. Timezone-aware. Free, offline, client-side,…

Convert Julian Date to Gregorian Date →

Convert Julian Day Number, Julian Calendar date, or ordinal date (YYYY-DDD) to Gregorian. Free, offline, client-side,…

Convert Julian Day to Date →

Convert Julian Day Number (JDN), Modified Julian Day (MJD), or NASA TJD to UTC date and…

Convert Military Time to Regular Time →

Convert 24-hour military time to 12-hour AM/PM (and reverse). Zulu, batch mode, all zone letters. Free,…

Convert Months to Days →

Convert months to days using Gregorian, Julian, or banking conventions - plus calendar-aware add-months. Free, offline,…

Convert Regular Time to Military Time →

Convert 12-hour AM/PM time to 24-hour military time and back. Handles seconds, noon/midnight, and batch lists.…

Convert Seconds to Time →

Convert seconds to HH:MM:SS, days/hours/minutes/seconds, words, and ISO 8601 duration. Reverse too. Free, offline, client-side, instant,…

Convert Time Between Countries →

Convert time between 53 countries with IANA DST handling, date picker, up to 3 targets. Free,…

Convert Time Between Timezones →

Convert time between any IANA timezones with DST handling, date picker, up to 3 targets. Free,…

Convert Time to Decimal →

Convert HH:MM:SS to decimal hours/minutes/seconds/days (and back). Batch, precision, formula. Free, offline, client-side, instant, secure.

Convert Time to Seconds →

Convert HH:MM:SS, ISO 8601, compact, words to total seconds (and back). Batch input. Free, offline, client-side,…

Convert Unix Time to Human Time →

Convert Unix timestamps to human dates in any timezone (s/ms/μs/ns). 6 formats, reverse direction, ISO 8601,…

Convert Weeks to Days →

Convert weeks to days (and back) with precision control and batch mode. Free, client-side, instant, secure.

Convert Years to Days →

Convert years to days with Gregorian, Julian, non-leap, or leap-year conventions. Bidirectional. Free, client-side, instant.

Date Format Converter →

Reformat a date into ISO, day-month-year, long, or full styles, in your browser.

Date Sequence Generator →

Generate a sequence of dates between a start and end date at a step in days.

Date-Time Series Generator →

Generate a series of date-times from a start point, count, and interval.

Day of the Week Finder →

Find which day of the week any date falls on, for any year, in your browser.

Days Until New Year Counter →

Count the days from any date to the next New Year, with the weekday of January…

Decrement Calendar Date →

Subtract years, months, days from any date with correct month-end clamping (March 31 minus 1 month…

Decrement Clock Time →

Subtract hours, minutes, seconds, milliseconds from any time with day-wrap counter, 12/24-hour display, fractional precision. Free,…

Draw Analog Clock →

Draw a real-time or custom analog clock in your browser. Sweeping second hand, Roman/Arabic numerals, 3…

Draw Digital Clock →

Live HH:MM:SS digital clock with 24-hour toggle, milliseconds, 3 themes, screenshot export. Free, offline, client-side, instant,…

Draw Memento Mori Calendar →

Draw Memento Mori Calendar online, free and private. Runs in your browser, no upload, instant and…

Draw Monthly Calendar →

Generate any month from year 1500-3000. Sunday/Monday week start, Today highlight, SVG/PNG export. Free, offline, client-side,…

Easter Sunday Date Finder →

Find the date of Western (Gregorian) Easter Sunday for any year from 1583 onward.

Find Chinese Zodiac Sign →

Find your Chinese zodiac animal AND element (Wood/Fire/Earth/Metal/Water + Yang/Yin) for any year. Free, offline, client-side,…

Find Christmas Day →

What weekday is Christmas? Dec 25 + Eve + NYE weekdays, leap-year, days-until, PTO advice. Free,…

Find Common Years →

List all common (365-day) and leap (366-day) years in a range. Counts, ratios, download. Free, offline,…

Find Date By Day of Year →

Convert between day-of-year (1-366) and calendar date - both directions, weekday, ISO ordinal, days remaining. Free,…

Find the Day of the Year →

Find the day-of-year number for any date, with the days remaining, leap years included.

Find the ISO Week of the Year →

Find the ISO 8601 week number for any date, with weeks starting on Monday.

Find the Nth Weekday of a Month →

Find the date of a specific weekday in a month, such as the first, third, or…

Find the Season for a Date →

Find the astronomical season for any date, for the Northern or Southern Hemisphere.

Format Time Duration Online →

Turn a number of seconds, minutes, or hours into a readable duration.

Friday the 13th Finder →

List every Friday the 13th in a given year, with the total count for that year.

Generate Fuzzy Calendar Dates →

Generate fuzzy calendar dates: translate exact dates into relaxed conversational phrases like "early next month" or…

Leap Year Finder →

Find every leap year within a range of years, with the total count.

List Holidays By Year →

List common holidays for any year, including fixed-date and floating holidays.

Mirror Clock Time →

Find the mirror image of a time as it would appear on an analog clock face.

Palindrome Clock Time Finder →

See every palindrome time on a 24-hour clock, like 12:21 or 23:32, with or without seconds,…

Palindrome Dates Finder →

Find palindrome dates within a year range, the dates whose digits read the same both ways.

Random Calendar Date Generator →

Generate random valid calendar dates within a year range, in ISO, US, or EU format.

Random Clock Time Generator →

Generate random clock times in the 24-hour or 12-hour format you choose, with optional seconds.

Random Unix Timestamp Generator →

Generate random Unix timestamps within a minimum and maximum you choose.

Round a Clock Time to Minutes →

Round a 24-hour clock time to the nearest 5, 10, 15, 30, or 60 minutes.

Round Calendar Date →

Round a calendar date to the nearest month or year, with up, down, or nearest modes.

Sort Calendar Dates →

Sort a list of calendar dates into chronological order, oldest or newest first.

Sort Clock Times →

Sort a list of 24-hour clock times into order, earliest or latest first.

Sort Date Ranges Online →

Sort a list of date ranges by their start date, with the end date as a…

Sort Time Ranges Online →

Sort a list of time ranges by their start time, with the end time as a…

Spell a Clock Time in Words →

Spell out a 24-hour clock time in plain English words, such as two thirty PM.

Spell a Date in Words →

Spell out a calendar date in plain English words, including the year.

Split Date Range Online →

Split a date range into a chosen number of equal intervals, with boundaries and ranges.

Split Time Range Online →

Split a time range into a chosen number of equal intervals, with boundaries and ranges.

Thanksgiving Day Date Finder →

Find the date of US or Canadian Thanksgiving for any year, by the standard rule.

Time Difference Calculator →

Find the duration between two clock times in hours, minutes, and seconds, overnight aware.

Time Sequence Generator →

Generate a sequence of clock times between a start and end at a step in minutes.

Truncate a Clock Time →

Truncate a clock time down to the hour or the minute by zeroing the smaller parts.

Truncate Calendar Date →

Truncate a calendar date down to the first day of its month or year.

Unix Timestamp Sequence Generator →

Generate a sequence of Unix timestamps from a start value, count, and step in seconds.

Unix Timestamp to Time Zone →

Convert a Unix timestamp to a readable date and time in the time zone you choose.

Validate Calendar Date →

Check whether calendar dates are valid, with correct months and days, in ISO, US, or EU…

Validate Clock Time →

Check whether clock times are valid, with correct hours, minutes, and seconds.

What Day Is July 4th →

Find which day of the week the Fourth of July falls on for any year.

Zodiac Sign by Date →

Find the Western zodiac star sign for any birth date, by month and day.