Date & Time
D-day, age, world time zone and calendar calculation utilities
Date & Time List
- Date Difference Calculator - Calculate the number of days between two dates, or the date N days from a reference date.
- D-Day Calculator - Show the days remaining until, or elapsed since, a target date based on today.
- Age Calculator - Calculate your exact age, this year's birthday status, and days until your next birthday.
- Time Calculator - Add or subtract time from a clock time, and calculate the interval between two times.
- Timestamp Converter - Convert Unix timestamps to readable dates and dates back to Unix timestamps.
- Months Between Dates Calculator - Calculate total months, days, and a year/month/day breakdown between two dates.
- Day of the Week Calculator - Find the day of the week for a date and its day difference from today.
- Leap Year Checker - Check whether a year is a leap year and how many days February has that year.
- Stopwatch - Measure time in milliseconds and record lap times.
- Countdown Timer - A countdown timer that alerts you when the set time reaches zero.
- Pomodoro Timer - A timer with 25-minute focus and 5-minute break cycles to boost concentration.
- Pregnancy Week Calculator - Calculate the pregnancy week and due date from the last menstrual period (LMP).
- Ovulation Calculator - Estimate ovulation day and the fertile window from the last period and average cycle.
- World Clock Converter - Convert a given date and time to the local time of major cities and time zones at once.
- Time Zone Converter - Convert a chosen date and time to another time zone's representation.
- Business Day Calculator - Calculate a date N business days out or the number of business days, excluding weekends.
- Week Number Calculator - Find which week of the year a date falls in, based on ISO 8601.
- Date Range Generator - Generate a list of all dates between a start and end date at once.
- Meeting Time Finder - Find times where working hours overlap across multiple time zones.
- Date Add/Subtract Calculator - Add or subtract days, weeks, months, or years from a reference date.
- Work Hours Calculator - Calculate work hours from clock-in, clock-out, and break time.
- Sleep Time Calculator - Calculate recommended bedtimes aligned to 90-minute sleep cycles based on your wake time.
- Unix Millisecond Converter - Auto-detect 10-digit second and 13-digit millisecond timestamps and convert to date/time.
- Alarm Clock - A simple alarm clock that runs in your browser and plays a synthesized beep.
- Leap Month Calculator - Check whether a lunar month is normal or leap, and find leap-month date ranges by year.
- Korean Zodiac Calculator - From a birth date, find the Korean zodiac sign by both Lunar New Year and Ipchun (solar term).
- Samjae Calculator - Determine Samjae (the three-year unlucky cycle) status from a zodiac sign and reference year.
- Zodiac Sign (Horoscope) Calculator - Find your Western zodiac sign from your solar birth date, with a personality summary.
- Korean Milestone Birthday Calculator - Calculate Korean traditional longevity celebration dates and D-days (Hwangap 60th, Chilsun 70th, etc.).
- 49-Day Memorial Calculator - Calculate Buddhist memorial dates from the first rite to the 49th-day rite, with weekdays and D-days.
- Sexagenary Cycle Calculator - Identify the sexagenary year, its symbolic animal and color, and trace years for a given cycle name.