Date & Time
Timezones, age, durations, countdowns, and timers.
- Add or Subtract Days from a DateAdd or subtract days, weeks, months, years, hours, or minutes from any date and see the resulting date instantly.
- Age CalculatorCalculate 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.
- Birthday Countdown - Days Until Your Next BirthdayFind 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.
- Chinese Zodiac Calculator - Find Your Animal Sign & ElementFind your Chinese zodiac animal sign, element, and Yin/Yang energy from your birth year. Includes personality traits, lucky colors, lucky numbers, and compatible signs.
- Countdown Timer - Free Online Countdown to Any DateCount 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.
- Day of the Week Calculator - What Day Was Any Date?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 Between DatesCalculate the exact number of days, weeks, months, and years between two dates. Toggle weekdays-only and include/exclude the end date.
- Days-Since / Sobriety CounterTrack how many days, weeks, months, and years have passed since any date. Perfect for sobriety, quit dates, and personal milestones.
- Easter Date Calculator - Find Easter Sunday for Any YearCalculate the date of Easter Sunday for any year using the Anonymous Gregorian (Butcher's) algorithm. Supports Gregorian and Julian calendar traditions.
- Equinox & Solstice Date Calculator - Astronomical SeasonsCalculate 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.
- Fiscal Quarter & Period CalculatorFind 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).
- Generation Finder - What Generation Am I?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.
- Golden Hour & Blue Hour Photography CalculatorCalculate 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.
- Great Circle / Haversine Distance CalculatorCalculate 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.
- Hebrew Calendar Converter - Jewish Date to GregorianConvert dates between the Hebrew (Jewish) calendar and the Gregorian calendar. Supports leap years with Adar I & II and all 12/13 Hebrew months.
- Hijri Calendar Converter - Islamic Date to GregorianConvert dates between the Hijri (Islamic) calendar and the Gregorian calendar. Uses the tabular Islamic calendar algorithm. Works entirely offline in your browser.
- Holiday Countdown - Days Until the Next HolidayCount the days until every major holiday. See upcoming holidays sorted by how soon they arrive, all calculated locally in your browser.
- ICS Calendar Event GeneratorCreate and download ICS (iCalendar) files for any event. Compatible with Google Calendar, Outlook, Apple Calendar, and any RFC 5545 calendar app.
- ISO Week Number CalculatorFind 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.
- Julian Date Converter - Gregorian to Julian Day NumberConvert between Gregorian calendar dates and Julian Day Numbers (JDN / JD). Also shows the equivalent Julian calendar date and Modified Julian Date (MJD).
- Leap Year & Days-in-Month CheckerCheck 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.
- Life Calendar - Weeks of Life VisualizerVisualize 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.
- Lunar Phase Calculator - Moon Phase for Any DateFind 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.
- Multi-Timezone Meeting PlannerPlan meetings across multiple cities and timezones. Visual overlap grid shows working hours for every participant. Download .ics or share a link.
- Pomodoro Timer - Free Online Focus TimerA 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.
- Stargazing Planner - Planet Visibility CalculatorCheck when Mercury, Venus, Mars, Jupiter, and Saturn are visible in the sky. Uses simplified orbital mechanics to predict planet elongation and visibility.
- Stopwatch - Free Online Stopwatch with Lap TimerFree online stopwatch with millisecond precision, lap recording, best/worst lap highlighting, and CSV export. Start, stop, lap, and reset. Runs entirely in your browser.
- Sunrise & Sunset Calculator - Sun Times for Any LocationCalculate sunrise, sunset, and solar noon for any latitude and longitude. Supports any UTC offset and detects polar day/night.
- Tidal Prediction Calculator - Tidal Harmonic ModelPredict 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.
- Time Card Calculator - Track Work Hours & OvertimeCalculate total work hours from clock-in and clock-out times. Add breaks, track overtime, and get a weekly summary. Supports overnight shifts.
- Time Duration Calculator - Add, Subtract & Multiply DurationsAdd, 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.
- Timezone Converter - Convert Time Between Time ZonesConvert 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.
- Unix Timestamp Converter - Epoch Time to Date & BackConvert 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.
- Wedding Anniversary Calculator - Gifts by YearEnter 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.
- Work Anniversary & Tenure CalculatorCalculate how long you have worked at a job - in years, months, and days - and find out when your next work anniversary is.
- Working Days CalculatorCount the number of business days between two dates, excluding weekends and public holidays for the US, UK, or Canada.
- World Clock - Live Time in Every TimezoneSee 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.
- Zodiac Sign Calculator - Find Your Western Astrology SignFind your Western zodiac (astrological) sign from your birth date. See personality traits, element, modality, ruling planet, and strengths and weaknesses.