Time & Date

Epoch & Unix Timestamp Converter

Converts an epoch/unix timestamp into a human readable date.

Age Calculator

Calculate your exact age in years, months, days, hours, minutes, and seconds. Find your zodiac sign and days until next birthday.

Birthday Calculator

Calculate your exact age in years, months, days and set calendar reminders for birthdays

Timer

Professional timer tool with countdown and stopwatch functionality for productivity and time management

Current Time

Display the current time in real-time with multiple time zones and formats

Stopwatch

Precise online stopwatch with lap times, split times, and multiple timer modes. Perfect for timing activities, workouts, cooking, and any time-sensitive tasks. No installation required, works directly in your browser.

Today's Date

Free online today's date tool to display current date and time in multiple formats, timezones, and calendars. Perfect for date references, scheduling, and time zone conversions. No registration required.

Draw Analog Clock

Create and customize analog clocks with different styles, colors, and time settings

Draw Memento Mori Calendar

Create a memento mori calendar that reminds you of mortality and the finite nature of life with customizable designs and philosophical quotes.

Draw Digital Clock

Create beautiful, customizable digital clocks with various styles, colors, and display options for websites, presentations, and personal use.

Draw Monthly Calendar

Create beautiful, customizable monthly calendars with various styles, colors, and display options for planning, scheduling, and personal use.

Generate Magic Clock Times

Generate magical clock times with special patterns like palindromes, repeated digits, sequential numbers, and other fascinating time combinations for fun and entertainment

Generate Magic Calendar Dates

Generate magical calendar dates with special patterns like palindromes, sequential numbers, repeated digits, and other fascinating date combinations for fun and entertainment

Convert Time to Seconds

Convert time formats (hours, minutes, seconds) to total seconds. Perfect for time calculations, duration measurements, and converting between different time units

Convert Seconds to Time

Convert total seconds to readable time formats (HH:MM:SS, HH:MM, etc.). Perfect for converting duration calculations, programming time values, and scientific measurements back to standard time formats

Convert 24hr to 12hr

Convert 24-hour time format to 12-hour format with AM/PM indicators. Easy time conversion tool for military time to standard time.

Convert 12hr to 24hr

Convert 12-hour time format to 24-hour format. Easy time conversion tool for standard time to military time with AM/PM handling.

Calculate Seconds Since Midnight

Calculate the number of seconds that have elapsed since midnight for any given time. Useful for time calculations and programming applications.

Calculate Seconds Till Midnight

Calculate the number of seconds remaining until midnight for any given time. Useful for countdown timers, scheduling, and time-based applications.

Find Time Difference

Calculate the time difference between two times. Get duration in hours, minutes, and seconds. Perfect for tracking work hours, meeting durations, and time intervals.

Find Date Difference

Calculate the number of days between two dates. Get precise date differences in days, weeks, months, and years. Perfect for project planning, age calculations, and date counting.

Find Age Difference

Calculate the age difference between two people. Compare ages in years, months, and days. Perfect for family relationships, generational gaps, and age-based analysis.

Increment Clock Time

Add hours, minutes, and seconds to any clock time. Calculate future times by incrementing time values. Perfect for scheduling, time planning, and time arithmetic.

Decrement Clock Time

Subtract hours, minutes, and seconds from any clock time. Calculate past times by decrementing time values. Perfect for scheduling, time planning, and time arithmetic.

Increment Calendar Date

Add days, weeks, months, or years to any calendar date with our free online date increment calculator. Perfect for scheduling, planning, and date arithmetic.

Decrement Calendar Date

Subtract days, weeks, months, or years from any calendar date with our free online date decrement calculator. Perfect for calculating past dates, deadlines, and date arithmetic.

Format Clock Time

Convert and format time between different formats like 12-hour, 24-hour, military time, and more. Perfect for time conversion, formatting, and standardization.

Format Calendar Date

Convert and format dates between different formats like ISO, US, EU, and more. Perfect for date conversion, formatting, and standardization.

Round Clock Time

Round time values to different intervals like minutes, hours, or custom periods. Perfect for time estimation, scheduling, and time calculations.

Round Calendar Date

Round dates to different intervals like days, weeks, months, or years. Perfect for date estimation, scheduling, and date calculations.

Truncate Clock Time

Truncate time values to different precision levels like seconds, minutes, or hours. Perfect for time simplification, data processing, and time calculations.

Truncate Calendar Date

Truncate dates to different precision levels like days, months, or years. Perfect for date simplification, data processing, and date calculations.

Sort Clock Times

Sort clock times ascending or descending instantly. Paste a list of times and get them organized for scheduling or logs. Free in your browser, no signup.

Sort Calendar Dates

Sort date values in ascending or descending order. Perfect for date organization, scheduling, and date calculations.

Sort Time Intervals

Sort time interval values in ascending or descending order. Perfect for time interval organization, scheduling, and time calculations.

Sort Date Intervals

Sort date interval values in ascending or descending order. Perfect for date interval organization, scheduling, and date calculations.

Validate Clock Time

Validate and check if clock time values are valid. Perfect for time validation, time format checking, and time verification.

Validate Calendar Date

Validate and check if calendar date values are valid. Perfect for date validation, date format checking, and date verification.

Convert Days to Hours

Convert days to hours with precision. Perfect for time conversion, duration calculations, and time unit conversions.

Convert Hours to Days

Convert hours to days with precision. Perfect for time conversion, duration calculations, and time unit conversions.

Average Clock Time Calculator

Calculate the average of multiple clock times with our free online calculator. Enter times in various formats and get instant results.

Average Calendar Date Calculator

Calculate the average of multiple calendar dates with our free online calculator. Enter dates in various formats and get instant results.

Split Time Into Intervals

Split a time period into equal intervals with our free online calculator. Perfect for scheduling, time management, and project planning.

Split Date Into Intervals

Split a date range into equal intervals with our free online calculator. Perfect for project planning, scheduling, and time management.

Generate Time Sequence

Generate sequences of times with our free online time sequence generator. Perfect for scheduling, time planning, and creating time-based sequences.

Generate Date Sequence

Generate sequential date lists with customizable intervals, formats, and filtering options

Find Leap Years

Find all leap years within a date range. Calculate leap years between two years with our free online leap year finder tool.

Find Common Years

Find all common years (non-leap years) between two years with detailed statistics and analysis.

Check Leap Year

Check if any year is a leap year with detailed explanation and leap year rules.

Check Common Year

Check if a year is a common year (non-leap year) with detailed explanation and common year rules

Gregorian Date To Julian Date Converter

Convert Gregorian calendar dates to Julian calendar dates. Accurate conversion tool for historical date calculations and calendar comparisons.

Julian Date To Gregorian Date Converter

Convert Julian calendar dates to Gregorian calendar dates. Accurate conversion tool for historical date calculations and calendar comparisons.

Convert Date To Julian Day

Convert any date to its corresponding Julian Day Number. Essential tool for astronomers, historians, and scientists working with continuous day counting systems.

Convert Julian Day To Date

Convert any Julian Day Number to its corresponding calendar date. Essential tool for astronomers, scientists, and researchers working with Julian Day Numbers.

Find Easter Dates

Calculate Easter Sunday dates for any year using the Computus algorithm. Find Easter dates for multiple years with detailed information about the calculation method.

Convert Human Time to Unix Time

Convert human-readable dates and times to Unix timestamps with support for multiple date formats and time zones.

Generate Unix Time Sequence

Generate sequences of Unix timestamps with our free online Unix time sequence generator. Perfect for testing, data generation, and creating timestamp sequences.

Generate Random Unix Time

Generate random Unix timestamps within a specified time range. Perfect for testing, data generation, and creating random time-based data.

Convert Regular Time to Military Time

Convert regular 12-hour time format to military 24-hour time format. Live conversion as you type with support for AM/PM and various time formats.

Convert Military Time to Regular Time

Convert military 24-hour time format to regular 12-hour time format. Live conversion as you type with support for various military time formats and AM/PM output.

Spell Clock Time

Convert clock time to words and text format

Spell Calendar Date

Convert calendar dates to words and text format

Add Fuzziness to Clock Times

Add randomness and approximation to precise clock times

Add Fuzziness to Calendar Dates

Add randomness and approximation to precise calendar dates

Find Day of Week

Calculate what day of the week any date falls on

Find Day of Year

Calculate what day of the year (1-365/366) any date falls on

Find Week of Year

Calculate what week of the year (1-52/53) any date falls on

Find Date by Day of Year

Calculate what date corresponds to a specific day of year (1-365/366)

Calculate Clock Hand Angle

Calculate the angle between hour and minute hands of a clock for any given time

Set Clock Hand Angle

Find the time that produces a specific angle between clock hands

Date Time Calculator

Calculate difference between two dates and times.

Friday The 13th Finder

Find every Friday the 13th between two dates. Filter by month, format output, choose delimiter.

Independence Day Finder

List US Independence Day (July 4) dates in a range. Optional weekday filter and date formats.

Christmas Day Finder

Find every Christmas Day date (December 25th) between two dates. Filter by weekday, format output, choose delimiter.

New Year's Day Finder

Find every New Year's Day date (January 1st) between two dates. Filter by weekday, format output, choose delimiter.

Thanksgiving Day Finder

Find the exact date of Thanksgiving for any year and country. Includes a countdown timer, monthly calendar highlight, and batch years generator.

Analyze Clock Time

Get detailed analysis of clock times including format, time of day, conversions to seconds, minutes, hours, time remaining till midnight, and spelled version.

Analyze Calendar Date

Get detailed analysis of calendar dates including day, month, year, century, day of week, week number, day of year, zodiac sign, leap year status, UNIX timestamp, Julian date, and spelled date in English.

Mirror Clock Time

Mirror a given clock time online.

Convert Time Between Timezones

Convert time between different timezones.

Convert Time Between Countries

Convert time between different countries.

Find Season by Date

Enter any date to find its season in the Northern or Southern Hemisphere. This free tool shows both meteorological and astronomical seasons, no signup required.

Hour Calculator

Calculate the exact hours and minutes between two times with this free online Hour Calculator. Track work hours, schedule shifts, and plan your day in seconds.

Working Days

Calculate the exact number of working days, business days, weekends, and holidays between any two dates with custom settings.

Time Calculator

Add or subtract time values, calculate time from dates, and parse time expressions

Time Card Calculator

Calculate work hours, overtime, and total pay with this time card calculator. Supports multiple employee entries, break deductions, hourly rates, and lunch breaks.

Roman Numeral Date Converter

Convert dates to Roman numerals and back. Choose from multiple date formats and delimiters for Roman numeral date conversion.

Countdown Timer

Count down to any event with our free online countdown timer. Track days, hours, minutes, and seconds until your special date.

Date ± Calendar Units Calculator

Add or subtract days, weeks, months, quarters or years from any date

Decimal to Time Calculator

Convert decimal numbers to hh:mm:ss time format

Time to Decimal Calculator

Convert hh:mm:ss time to decimal hours, minutes, and seconds

Time Duration Calculator

Calculate the exact duration between two times in hours, minutes, and seconds. Free online time duration calculator with instant results.

Autumnal Equinox Day

Find the exact date, time, and countdown of the autumnal equinox for any year in both Northern and Southern hemispheres.

Commute Life Wasted Calculator

Calculate the total days, months, and years of your life spent commuting to work. Enter your daily round-trip travel time and years worked to see the staggering total.

Daily Time Savings Calculator

Calculate how much time you can save per year by saving just a few minutes each day. Discover the cumulative impact of small daily time savings.

Date Calculator

Add or subtract days, weeks, months, and years to or from any date with step-by-step calculations, business day tracking, and comprehensive date insights.

Date Pattern Generator

Create lists of recurring dates by pattern (daily, weekly, monthly) with weekend and holiday handling.

Day of Year Calendar

Interactive calendar showing day-of-year numbers (1-365/366) for any year with quick date lookup and quarter breakdowns.

Days in Month

Calculate how many days are in any month of any year, with leap year detection and quarterly comparisons.

Decimal to Time Converter

Convert decimal hours or decimal degrees to time format (hours, minutes, seconds) instantly with step-by-step breakdown.

First Day of Autumn

Find the exact date and time of the first day of autumn (fall equinox) for any year. Includes hemisphere selection and comprehensive seasonal information.

First Day of Spring

Find the exact date and time of the first day of spring (vernal equinox) for any year. Includes hemisphere selection and comprehensive seasonal information.

First Day of Summer

Find the exact date and time of the first day of summer (summer solstice) for any year. Includes hemisphere selection and comprehensive seasonal information.

First Day of Winter

Find the exact date and time of the first day of winter (winter solstice) for any year. Includes hemisphere selection and comprehensive seasonal information.

Golden Hour Blue Hour Calculator

Calculate exact golden hour and blue hour times for any location and date. Get optimal photography lighting windows with sunrise, sunset, and twilight schedules.

Hijri Calendar Converter

Convert dates between Gregorian and Hijri (Islamic) calendars bidirectionally. See Arabic month names, Arabic-Indic numerals, Islamic holidays, and countdowns to major Islamic events.

Mercury Retrograde Calendar

Check if Mercury is retrograde now. View complete Mercury retrograde dates, shadow periods, and zodiac signs for any year (1900-2100) with Swiss Ephemeris accuracy.

New Moon Full Moon Calendar

Find precise dates and times of all New Moons and Full Moons for any year from 1900 to 2100. Includes zodiac positions, spiritual meanings, and intention guidance for each lunar phase.

Next Leap Year Calculator

Find the next leap year from any given year with visual timeline, leap year checker, and educational content about the Gregorian calendar 400-year cycle.

Week Calculator

Calculate the exact number of weeks and days between any two dates with our free online week counter. Shows week numbers and day of week for both dates.

Minutes to Days Converter

Enter any number of minutes and this free converter instantly shows the equivalent in days, plus a full breakdown in hours, minutes, seconds, and weeks.

Minutes to Seconds Converter

Convert minutes to seconds and seconds to minutes instantly with bidirectional real-time results.

Minutes to Years Converter

Convert minutes to years, months, days, and hours with instant results and full time breakdown.

Months to Years Converter

Convert months to years and years to months with years/months breakdown notation.

Seconds to Days Converter

Convert seconds to days and days to seconds instantly with bidirectional real-time results.

Seconds to Hours Converter

Convert seconds to hours and hours to seconds instantly with bidirectional real-time results.

Seconds to Years Converter

Convert seconds to years and years to seconds instantly with bidirectional real-time results.

Month Calculator

Calculate future or past dates by adding or subtracting months from any start date with instant results.

Hours Calculator

Find the number of hours and minutes between two times or add and subtract hours from a start time.

Days Calculator

Calculate the exact number of days, weeks, and months between any two dates instantly.

Weeks to Months Converter

Convert weeks to months and months to weeks with related day, hour, and year breakdowns in real time.

Weeks to Years Converter

Convert weeks to years and years to weeks using the standard 52.18 weeks per year factor with full time breakdowns.

Years to Decades Converter

Convert years to decades and decades to years with centuries and millennium breakdowns using the 10 years per decade factor.

100 Day Calculator

Calculate the calendar date that falls a set number of days after any start date, with an option to include the start date in the count.

120 Day Calculator

Find the calendar date 120 days after any start date. Adjust the day count for milestones, trials, and deadlines.

Age to Birthday Calculator

Convert your age to your birthday date instantly. Free online age to birthday converter tool that calculates your exact birth date from your current age.

Anniversary Calculator

Calculate how long you've been married or together with our free anniversary calculator. See years, months, days and traditional gift ideas.

Baby Age Calculator

Calculate your baby's exact age in years, months, weeks, and days. Generate a milestone calendar for the first 24 months with day-of-week and age details.

BC to AD

Calculate the exact number of years between a BC (Before Christ) and an AD (Anno Domini) year. Simple year difference calculator with historical timeline context.

Birthday Countdown Calculator

Find out exactly how many days, hours, and minutes until your next birthday with our live birthday countdown calculator. Track the time remaining until your special day.

Birth From Death Date Calculator

Calculate the birth date from a death date and age at death. Useful for genealogy research and finding ancestral birth dates.

Birth Year Calculator

Calculate your birth year based on your age and a specific date. Simply enter your age and the reference date to find out what year you were born.

Business Days

Count business days between two dates, skip weekends, and exclude optional holidays. This free working days calculator runs in your browser with no signup.

Calendar Countdown

Calculate the exact number of days between two dates with our free calendar countdown calculator. Simple and accurate date difference tool.

Chronological Age Calculator

Calculate your exact chronological age in years, months, weeks, days, hours, minutes, and seconds. Free online chronological age calculator with custom date support.

Countdown Calculator

Calculate the exact time remaining between two dates. Free online countdown calculator showing years, months, days, hours, minutes, and seconds.

Count Hours Calculator

Add up multiple time entries to calculate total hours worked. Free online count hours calculator for payroll, timesheets, and time tracking.

Date Countdown

Calculate the exact countdown between any two dates with days, hours, minutes, and seconds.

Date of Birth Calculator

Enter an age and a reference date to find the exact date of birth, or work backward from a birth date to calculate current age instantly. Free, no signup.

Days Until December

Calculate how many days remain until December 1st from any start date. Plan holidays, winter trips, and year-end events with an instant countdown.

Days Until June

Calculate exactly how many days remain until the 1st of June from any date. Plan your summer countdown with our free online days until June calculator.

Deadline Calculator

Calculate deadlines by adding or subtracting days, weeks, months, or years from any date. Automatically adjusts for weekends and federal holidays with our free online deadline calculator.

Elapsed Time Calculator

Calculate elapsed time between two clock times, or find the end time from a start time and duration. Free online elapsed time calculator with instant results.

Time Spent on Email Calculator

Find out how much time you spend on emails daily, monthly, and until retirement. Discover alternative activities you could do with the time saved.

Every Second Calculator

Discover fascinating statistics about what happens every second around the world - births, internet activity, economic data, and more.

Expiration Date Calculator

Calculate expiration dates for products based on production date and shelf life. Determine when food, cosmetics, and other products expire.

Half Birthday Calculator

Calculate your half birthday date, next birthday, and next half birthday. Find out when exactly 6 months after your birth date falls.

Hours to Minutes Converter

Convert hours to minutes and minutes to hours with our free online converter. Real-time conversion, formulas, and detailed breakdowns.

Korean Age Calculator

Calculate your Korean age from birth year or international age. Understand Korea's unique age counting system with instant results.

Lunar Age Calculator

Find your age in the Chinese lunar and Hijri calendars. Enter your birth date to apply Chinese New Year and pregnancy-year adjustments - free and instant.

Minutes Between Two Times

Calculate the exact number of minutes between two times of the day. Free online minutes between two times calculator with instant results.

Month Counter Calculator

Count the number of months between two dates, add or subtract months from any date, and track month milestones. Free online month counter.

Months Between Dates

Calculate the exact number of months between any two dates with our free online months between dates calculator. Perfect for billing cycles, project planning, and date calculations.

Moon Phase

Find the Moon phase for any date with our free online moon phase calculator. See new moon, full moon, first quarter, last quarter, and all lunar phases instantly.

Number of Days

Calculate the exact number of days between any two dates with our free online number of days calculator. Includes business days, weekends, and custom day counting options.

Palindrome Date Finder

Find palindrome dates between any two dates with various date formats and discover upcoming palindromic calendar days.

Reverse Time Calculator

Convert occurrence rates between different time units. Enter how many times something happens per year, month, week, day, hour, minute, or second and see equivalents in all other units instantly.

Sidereal Time Calculator

Calculate Greenwich Mean Sidereal Time (GMST) and Local Sidereal Time (LST) based on date, time, and longitude.

Time Adder Calculator

Add up to 20 time values with hours, minutes, and seconds using our free online time adder calculator. Get total time in any unit.

Man Hours Calculator

Easily calculate total man-hours, labor capacity, project duration, and labor costs for any project or workforce with this free browser tool. No signup needed.

Days Off Calculator

Calculate your legally entitled paid leave and vacation days based on your country, contract type, and work hours.

Time Percentage Calculator

Calculate what percentage of time a duration takes of another total period or find a duration from a percentage with step-by-step breakdown.

Age on Other Planets Calculator

Calculate your age on Mercury, Venus, Mars, Jupiter, and every planet in the solar system from your birthday or current age.

Recruitment Process Duration Calculator

Estimate total recruiter hours for CV screening, interviews, and offer discussions across multi-round hiring workflows.

Days Until Christmas

Count how many days remain until Christmas Day (December 25) from any start date with weeks breakdown and year-end planning stats.

Days Until Fall

Calculate days until the first day of fall from any date using the autumnal equinox for Northern or Southern Hemisphere with instant countdown.

Days Until Valentines Day

Count how many days remain until Valentine's Day (February 14) from any start date with weeks breakdown and planning stats.

Mayan Calendar Converter

Convert Gregorian dates to Mayan Long Count, Tzolkin, and Haab calendar components.

New Years Countdown

Watch a live countdown with days, hours, minutes, and seconds until the next New Year at midnight.

Time Lapse Calculator

Plan time-lapse shoots by calculating shooting interval, clip duration, playback fps, and real-world time covered.

30 Day Calculator

Calculate a date 30 days before or after any starting date for monthly deadlines and planning.

30 Minute Timer Calculator

Add or subtract 30 minutes from any clock time to get the new time with AM/PM formatting.

45 Day Calculator

Add or subtract 45 days from any date for project timelines and return deadlines.

60 Day Calculator

Calculate dates 60 days before or after a start date for two-month planning windows.

6 Month Calculator

Add or subtract six months from any date with calendar-aware month and year rollover.

180 Day Calculator

Add or subtract 180 days from any date to find deadlines, half-year milestones, and calendar results.

90 Day Calculator

Calculate a date 90 days before or after any starting date for quarterly deadlines and planning.

Add Days Calculator

Add or subtract any number of days from a date to find future or past calendar dates instantly.

Age In Days Calculator

Calculate your exact age in total days from your birth date with instant results.

Age In Hours Calculator

Find how many hours old you are from your birth date with live hour totals.

Age In Minutes Calculator

Calculate your age in total minutes lived since birth with precise results.

Age In Months Calculator

Convert your birth date to total months lived with calendar-accurate month counting.

Age In Seconds Calculator

Calculate your exact age in total seconds lived since birth with real-time updates.

Age In Weeks Calculator

Find your age in total weeks and remaining days from your birth date.

Age In Years Calculator

Calculate your age in decimal years from your birth date with precise day-based math.

Age In Years Months And Days Calculator

Calculate your age broken down into years, months, and days from any birth date.

Date Formatter

Format any date and time as ISO 8601, US, EU, long, short, Unix timestamp, and custom token patterns with instant copy ready output.

Holiday Calendar

View public holidays by country and year with weekday labels, weekend substitution dates, and a live countdown to upcoming holidays.

Quarter Calculator

See the quarter number, start and end dates, days remaining, and a full-year quarter list for a calendar year or a custom fiscal year start.

Ramadan Calendar

Estimate Ramadan dates for any year and list daily Suhoor and Iftar times for a chosen city using prayer-time math in the browser.

Date to LDAP Timestamp Converter

Convert calendar dates to Windows LDAP/Active Directory timestamps (100-ns intervals since 1601) with UTC and local time support.

LDAP Timestamp to Date Converter

Convert Active Directory LDAP or Windows FILETIME integers into readable dates with UTC and local display.

Mac HFS Timestamp Converter

Convert Mac HFS+ seconds-since-1904 timestamps to readable dates and back, with Unix time cross-reference.

Milliseconds Calculator

Calculate the exact millisecond difference between two dates and times with a detailed breakdown.

MongoDB ObjectId to Timestamp Converter

Extract the creation timestamp embedded in a MongoDB ObjectId and view it in local time, UTC, and ISO formats.

SAS Timestamp Converter

Convert SAS datetime values to readable dates and encode calendar dates into SAS seconds since 1960-01-01.

Unix Hex Timestamp Converter

Convert Unix timestamps in hexadecimal to human-readable dates and encode dates as hex epoch values.

WebKit Chrome Timestamp Converter

Convert WebKit and Chrome microsecond timestamps to calendar dates and encode dates for browser history debugging.

Date Add Subtract

Add or subtract days, weeks, months, or years from any date with instant results.

Date Format Converter

Parse messy date strings and view them in ISO 8601, US, EU, RFC 2822, and locale formats at once.

Date Range Splitter

Divide a start and end date into equal chunks or fixed day/week/month intervals with a table preview.

Day Percentage Elapsed

See how much of the current year, month, or custom range has elapsed as a percentage.

Duration Converter

Convert time spans between seconds, minutes, hours, days, weeks, and ISO-8601 duration strings.

Duration Humanizer

Turn second counts or ISO durations into plain English phrases like 2 hours and 15 minutes.

Duration Parser

Parse compact and natural language durations like 1h30m or 2 days 4 hours into total seconds and milliseconds.

Epoch Precision Converter

Convert Unix timestamps between second, millisecond, microsecond, and nanosecond precision with auto-detection.

Fixed Offset Timezone Math

Add or subtract fixed UTC offsets, convert between zones without DST, and compare instants.

Next Weekday Occurrence

List upcoming dates that fall on Monday through Sunday from any start date, with offsets and copy-friendly output.

Nth Weekday of Month

Compute dates like the third Thursday of November or the last Monday of May for scheduling and calendar rules.

Ordinal Date Converter

Convert between ISO calendar dates and ordinal dates (year plus day-of-year 1-366) with leap-year aware math in your browser.

Day Counter

Calculate the exact number of days between two dates. Count forward or backward with leap years handled automatically.

Days Between Dates

Find the exact number of days between two calendar dates, including leap years and month boundaries.

Recurring Event Dates

List upcoming dates for daily, weekly, monthly, or yearly recurring events between two calendar dates.

Relative Time Formatter

Format past and future timestamps as human-readable relative phrases such as in 3 days or 2 hours ago.

Work Hours Calculator

Calculate total hours worked from start and end times with break deductions. Sum daily hours for payroll and timesheets.

Unix Nanoseconds Converter

Convert nanosecond-precision Unix timestamps to ISO dates and back using BigInt math without float loss.

Timestamp Batch Converter

Convert many Unix epoch timestamps to ISO dates or dates back to epoch in one paste, with per-line errors.

Time Duration Arithmetic

Sum or subtract HH:MM:SS durations with a running total and signed result for logs and payroll.

Time Unit Converter

Convert values between nanoseconds, microseconds, milliseconds, seconds, minutes, hours, and days with precise factors.

Fixed Offset Meeting Planner

See one meeting time across multiple fixed UTC offsets and check overlap with working-hour windows.

Unix Rollover Checker

See Year 2038, Y2K, NTP era, GPS week, and 64-bit time limits with exact UTC dates.

Weekday of Date

Find the day of the week for any calendar date and follow a step-by-step Doomsday-rule walkthrough in your browser.

Week of Month Finder

See which week of the month a date falls in using Sunday-start, Monday-start, 7-day block, or ISO partial-week conventions.

Week to Date

Convert ISO 8601 week-year and week number to Monday–Sunday dates, or look up the ISO week for any calendar date.

Add Business Days

Add or subtract business days from a start date, skipping weekends and custom holidays. Free working-day calendar calculator in your browser.