Every Date Tool
You'll Ever Need
Free, instant date and time calculators. Calculate ages, find date differences, convert time zones, set countdowns, and more — no sign-up required.
Tools
Click any tool to use it instantly
Age Calculator
Calculate your exact age in years, months, days, hours and minutes.
Date Difference
Find the exact number of days, weeks, or months between two dates.
Countdown Timer
Count down to any future event — New Year, birthday, deadline.
Time Zone Converter
Convert time across world time zones instantly.
Working Days Calculator
Calculate business days between dates, excluding weekends and holidays.
Add / Subtract Days
Add or subtract any number of days, weeks, or months from a date.
Unix Timestamp
Convert Unix timestamps to human-readable dates and vice versa.
Week Number
Find the ISO week number for any date of the year.
Leap Year Checker
Check if any year is a leap year and when the next one is.
World Clock
See the current time in major cities around the world.
Zodiac & Chinese Sign
Find your Western zodiac sign and Chinese zodiac animal by birthday.
Day of Year
Find what day number of the year any date falls on.
Articles
Learn about dates, time, and calendars
Why Does a Year Have 365 Days?
The fascinating astronomy and history behind our 365-day calendar year.
How Time Zones Work: The Complete Guide
From Greenwich Mean Time to UTC offsets — everything you need to know.
The History and Rules of Leap Years
Why we add an extra day every four years, and the exceptions to the rule.
Unix Timestamps Explained Simply
What is a Unix timestamp, why does it start from 1970, and why it matters.
How to Schedule Meetings Across Time Zones
Practical strategies for coordinating with remote teams around the world.
A Brief History of Calendars
From lunar calendars to the Gregorian system — humanity's quest to track time.
Daylight Saving Time: A Complete Guide
Why we change the clocks twice a year, who started it, and the ongoing debate to abolish it.
UTC vs GMT: What's the Difference?
These two terms are often used interchangeably — but they aren't quite the same thing.
The Year 2038 Problem Explained
Why some computers will run out of time on January 19, 2038 — and what's being done.
Why Does a Week Have Seven Days?
The ancient Babylonian and astronomical roots of our seven-day week.
How to Calculate Your Exact Age
Different methods for calculating age, and why your 'age' depends on the calendar system.
How Atomic Clocks Keep Perfect Time
The science behind the most accurate timekeeping devices ever built.
ISO 8601: The International Date Standard
Why YYYY-MM-DD is the only date format that makes sense for computers and humans.
How to Calculate Business Days
Counting working days correctly means handling weekends, holidays, and regional differences.
What Are Leap Seconds?
Occasionally we add a single second to the clock. Here's why — and why it may be abolished.
The Chinese Zodiac: A Complete Guide
The twelve animals, the sixty-year cycle, and how your birth year shapes your sign.
The Twelve Western Zodiac Signs Explained
How the constellations along the ecliptic became the basis for astrology.
Birthstones by Month: The Complete List
Discover the traditional and modern gemstone associated with every birth month.
The Pomodoro Technique: Work in Focused Bursts
How a simple kitchen timer method can transform your productivity and focus.
7 Proven Time Management Techniques
From time blocking to the Eisenhower matrix — methods that actually work.
Understanding ISO Week Numbers
How businesses and schedules use week numbers, and how to calculate them correctly.
From Sundials to Smartwatches: A History of Clocks
The 5,000-year journey of humanity's quest to measure the passing of time.
The Gregorian Calendar Reform of 1582
How ten days vanished from October 1582, and why countries adopted it centuries apart.
How Computers Store Dates and Times
Behind every timestamp is a clever system of counting from a fixed reference point.
Why Is Friday the 13th Considered Unlucky?
The surprising history behind one of the Western world's most enduring superstitions.
Counting Down to the New Year
Different cultures celebrate the new year on different dates — here's the fascinating variety.
Does Time Really Flow at the Same Speed?
Einstein showed that time is relative — moving clocks and gravity actually change time itself.
Lunar vs Solar Calendars: Key Differences
Why some calendars follow the moon, some the sun, and some try to track both.
What Is Epoch Time?
Understanding the reference points computers use to measure time across systems.
How to Plan Backwards From a Deadline
A practical framework for breaking big goals into dated milestones that actually get done.
Tools That Work Together
Each tool shows you related tools for connected tasks. Calculate an age, then check the day of the week you were born. Convert a timezone, then count down to your meeting. Everything flows naturally.
See all toolsFrequently Asked Questions
Quick answers to common time and date questions
Time Well Calculated
All tools are free, fast, and work directly in your browser. No account, no downloads, no ads interrupting your work.
Start Using Tools