About HowManyDays.org
We didn't just build another date calculator. We built the date calculator we wished existed when we needed it most.
Our site is constantly expanding, with new date calculation features being added regularly to help people track important moments in their lives.
Our Time-Obsessed Origin Story
It all started with a missed important date and a realization that keeping track of days between dates is surprisingly difficult in our busy digital lives.
While most calendar apps tell you when an event is happening, few tell you how many days until (or since) that date—information that's often more meaningful for planning, anticipation, or reflection.
Why We're Different
- No unnecessary complexity — we focus solely on date calculations, doing that one thing extremely well
- Privacy-centric design — no account required, no tracking of your personal dates
- Scientifically accurate — our algorithms account for leap years, calendar anomalies, and time zones
- Accessible to everyone — designed with readability and assistive technology in mind
Fun Facts About Time (That Keep Us Up At Night)
The concept of a 24-hour day dates back to ancient Egypt, who divided day and night into 12 hours each (regardless of actual daylight duration).
A day on Earth is actually getting longer by about 1.7 milliseconds per century due to the slowing of Earth's rotation.
The International Date Line isn't a straight line! It zigzags through the Pacific Ocean to accommodate political boundaries and keep certain island groups on the same calendar day.
February 30th actually existed in Sweden in 1712 as part of a failed calendar transition.
Get In Touch
Have suggestions for improving our calculator? Or just want to share an interesting time fact? Our door (and inbox) is always open.