📅 Date & Time Calculators

📅

D-day Calculator

Calculate D-day to exam date, elapsed days, date 100 days later, etc.

⏰

Time Calculator

Provides various time calculations including time difference, time addition, timezone conversion.

📊

Months Calculator

Accurately calculate period between two dates in months, weeks, and days.

🐕

Dog Age Calculator

Convert dog age to human years. Size-specific calculations provided.

🐱

Cat Age Calculator

Convert cat age to human years. Indoor/outdoor distinction provided.

🌍

World Clock

Automatically display major city times and time differences.

👶

Pregnancy Calculator

Automatically calculate due date and ovulation date from last menstrual period.

🎂

Age Calculator

Calculate international age, Korean age, and year age from your date of birth.

📆

Business Days Calculator

Calculate the number of business days excluding weekends/holidays, or find the date N business days from a start date.

🌙

Moon Phase Calculator

Calculate the moon phase for any date and the days remaining until the next new or full moon.

🌅

Sunrise & Sunset Calculator

Calculate sunrise, sunset, and day length for any location and date.

☀️

Sun Position Calculator

Calculate the sun's altitude and azimuth for any location and time.

🔢

Julian Day Converter

Convert between Gregorian calendar dates and Julian Day (JD) numbers.

🗓️

Leap Year Checker

Check whether a given year is a leap year and see how many years until the next one.

🗓️

Week Number Calculator

Calculate the ISO week number (which week of the year) for any date.

📐

Midpoint Date Calculator

Calculate the exact midpoint date between two dates.

🎈

Half Birthday Calculator

Calculate the exact date that falls exactly six months after your birthday.

✡️

Hebrew Calendar Converter

Convert dates between the Gregorian and Hebrew (Jewish) calendars.

☪️

Hijri Calendar Converter

Convert dates between the Gregorian and Hijri (Islamic) calendars.

🗓️

Date Pattern Generator

Generate a list of dates matching a recurrence pattern (weekly, monthly, etc.).

🎯

Sobriety Calculator

Calculate how long you've been sober and how much money you've saved since your sobriety date.