Time Unit Converter

Convert between different time units from milliseconds to cosmic scales including light years and eons. See real-world comparisons to understand time durations better, from everyday activities to geological and cosmic events.

How to Use This Tool

The Time Unit Converter makes it easy to switch between seconds, minutes, hours, days, and more. Enter any positive number in the input field, then pick your starting unit from the dropdown. Use the quick select buttons for common values like one hour or one day. You can also adjust the precision to control how many decimal places you see. Change the display format to fit your needs, whether you want a simple or detailed view.

All conversions appear in real time as you type. You can see how one unit compares to others instantly. To make results easier to grasp, the tool adds real-world examples that show what each duration feels like in daily life. Copy any result directly to your clipboard for quick sharing or calculations. It's fast, accurate, and made for anyone who works with time measurements.

Fun Facts About Time

1. A second was once measured by the swing of a clock's pendulum. Today it is based on the vibration of a cesium atom, which ticks 9,192,631,770 times per second. There are about 31.5 million seconds in a year.
2. A year on Venus is shorter than a day on Venus. The planet takes 225 Earth days to orbit the sun but spins so slowly that one full day lasts 243 Earth days.
3. The word minute comes from the Latin phrase pars minuta prima, which means “first small part.” The word “second” comes from pars minuta secunda, meaning “second small part.”
4. A fortnight means fourteen nights, or two weeks. The word comes from Old English feowertyne niht, meaning “fourteen nights.” People in the United Kingdom and other Commonwealth countries still use it to measure short spans of time. In online games like Fortnite, the name is a playful twist on the same word.
5. A year is the time Earth takes to orbit the Sun once, about 365 days. Because the orbit is not perfect, we add one extra day every four years, called a leap year.
6. A century equals 100 years. It is long enough to see massive changes in history, science, and culture. The 20th century alone brought flight, space travel, and the internet.
7. A millennium is 1,000 years. Civilizations rise and fall in that span. The Great Pyramid of Giza, built around 2560 BCE, has seen more than four millennia pass.
8. A light-year is not a measure of time but of distance. It is how far light travels in one year—about 9.46 trillion kilometers or 5.88 trillion miles. When you look at stars, you see light that left them years ago, so you are looking into the past.
9. An eon is the largest unit of geological time. It can last billions of years. Earth itself is about 4.5 billion years old, or one full eon of planetary history.