Date & Time
38 toolsTimezones, age, durations, countdowns, and timers.
Dates are surprisingly hard: months have uneven lengths, timezones shift, and "90 days from today" is rarely something you want to count on your fingers. These tools do the calendar math for you, from simple date differences to working-day counts and recurring milestones.
There are also clocks and timers for daily use, converters for religious and historical calendars, and a small astronomy corner for sunrise, moon phases, and golden hour.
Most popular
Date Math
- Date Difference Calculate the exact number of days, weeks, months, and years between two dates. Toggle weekdays-only and include/exclude the end date.
- Date Add/Subtract Add or subtract days, weeks, months, years, hours, or minutes from any date and see the resulting date instantly.
- Working Days Count the number of business days between two dates, excluding weekends and public holidays for the US, UK, or Canada.
- Day of Week Calculator Find out what day of the week any date falls on. Shows the day name, week number, day of year, quarter, and more. Also find the next occurrence of any weekday.
- Days Since Track how many days, weeks, months, and years have passed since any date. Perfect for sobriety, quit dates, and personal milestones.
- Week Number Calculator Find the ISO 8601 week number for any date. See the week year, day of the week, and the exact Monday-Sunday date range for the selected week.
- Leap Year Calculator Check if any year is a leap year, see the number of days in each month, find the next and previous leap years, and explore why 1900 was not a leap year.
- Age Calculator Calculate your exact age in years, months, and days. See total days, weeks, hours, next birthday countdown, zodiac sign, and day of week you were born.
- Anniversary Calculator Enter your wedding date to find out how many years you have been married and discover the traditional and modern gift themes for each anniversary year.
- Tenure Calculator Calculate how long you have worked at a job - in years, months, and days - and find out when your next work anniversary is.
- Time Duration Calculator Add, subtract, multiply, divide, or average a list of HH:MM:SS durations without calendar dates. Get results in HH:MM:SS, total seconds, minutes, and decimal hours.
- Fiscal Quarter Calculator Find the fiscal quarter, fiscal year, and days remaining for any date. Supports custom fiscal year start months (e.g. April for UK, October for US federal).
Clocks & Timers
- Pomodoro Timer A fully configurable Pomodoro timer with 25-minute work sessions, short breaks, and long breaks. Audio chime, browser notifications, and daily pomodoro count. Runs in your browser.
- Countdown Timer Count down to any future event: a New Year, vacation, product launch, or deadline. Live days, hours, minutes, and seconds. Save multiple countdowns and share via link. Runs in your browser.
- Stopwatch Free online stopwatch with millisecond precision, lap recording, best/worst lap highlighting, and CSV export. Start, stop, lap, and reset. Runs entirely in your browser.
- Time Card Calculator Calculate total work hours from clock-in and clock-out times. Add breaks, track overtime, and get a weekly summary. Supports overnight shifts.
- World Clock See the current time in multiple cities and timezones simultaneously. Live-updating clocks with date, UTC offset, and DST indicator. Add your own zones, saved automatically to your browser.
Timezones & Scheduling
- Timezone Converter Convert any date and time between multiple time zones instantly. Shows UTC offset, DST status, and day/night indicator. Uses the full IANA timezone database. Runs in your browser.
- Meeting Planner Plan meetings across multiple cities and timezones. Visual overlap grid shows working hours for every participant. Download .ics or share a link.
- Unix Timestamp Converter Convert Unix timestamps (epoch time) to human-readable dates and back. Auto-detects seconds vs milliseconds. Shows ISO 8601, RFC 2822, UTC, and local time. Live current timestamp for developers.
- ICS Generator Create and download ICS (iCalendar) files for any event. Compatible with Google Calendar, Outlook, Apple Calendar, and any RFC 5545 calendar app.
Countdowns & Milestones
- Birthday Countdown Find out exactly how many days until your next birthday, what age you will be, and what day of the week your birthday falls on. Free, instant, no sign-up required.
- Holiday Countdown Count the days until every major holiday. See upcoming holidays sorted by how soon they arrive, all calculated locally in your browser.
- Life Calendar Visualize your life as a grid of weeks. Enter your birth date and life expectancy to see which weeks have passed and how many remain - inspired by the famous "Your Life in Weeks" concept.
- Generation Finder Enter your birth year to find out which generation you belong to - Gen Z, Millennial, Gen X, Baby Boomer, Silent Generation, or Gen Alpha - along with defining events and characteristics.
Calendars & Traditions
- Easter Date Calculator Calculate the date of Easter Sunday for any year using the Anonymous Gregorian (Butcher's) algorithm. Supports Gregorian and Julian calendar traditions.
- Chinese Zodiac Calculator Find your Chinese zodiac animal sign, element, and Yin/Yang energy from your birth year. Includes personality traits, lucky colors, lucky numbers, and compatible signs.
- Zodiac Sign Calculator Find your Western zodiac (astrological) sign from your birth date. See personality traits, element, modality, ruling planet, and strengths and weaknesses.
- Julian Date Converter Convert between Gregorian calendar dates and Julian Day Numbers (JDN / JD). Also shows the equivalent Julian calendar date and Modified Julian Date (MJD).
- Hijri Calendar Converter Convert dates between the Hijri (Islamic) calendar and the Gregorian calendar. Uses the tabular Islamic calendar algorithm. Works entirely offline in your browser.
- Hebrew Calendar Converter Convert dates between the Hebrew (Jewish) calendar and the Gregorian calendar. Supports leap years with Adar I & II and all 12/13 Hebrew months.
Sun, Moon & Sky
- Sunrise / Sunset Calculate sunrise, sunset, and solar noon for any latitude and longitude. Supports any UTC offset and detects polar day/night.
- Golden Hour Calculator Calculate sunrise, sunset, golden hour, and blue hour times for any location and date. Perfect for photographers wanting to plan the perfect shot at the best natural light.
- Lunar Phase Calculator Find the moon phase for any date. Shows the current lunar phase, illumination percentage, moon age, and the dates of the next new moon and full moon.
- Equinox Calculator Calculate the precise dates and times of the March equinox, June solstice, September equinox, and December solstice for any year from 1000 to 3000, using Jean Meeus astronomical algorithms.
- Stargazing Planner Check when Mercury, Venus, Mars, Jupiter, and Saturn are visible in the sky. Uses simplified orbital mechanics to predict planet elongation and visibility.
- Tidal Prediction Predict tidal heights using a simplified harmonic model based on the major lunar and solar tidal constituents. View a 48-hour tide curve and find high/low tide times.
- Haversine Calculator Calculate the great-circle distance between two points on Earth using the Haversine formula. Returns distance in km and miles, initial bearing, and the geographic midpoint.
No tools match your filter.
Try a different keyword, or clear the filter.