D-Day Calculator
Calculate D-Day until your target date with real-time countdown and auto-save.
D-Day Calculator
Set Your D-Day
About D-Day Counting
- D-Day: The target date itself
- D-N: N days until target date
- D+N: N days since target date
to calculate D-Day
What is a D-Day Calculator?
A D-Day Calculator is a tool that calculates the number of days remaining until or elapsed since a specific target date. You can easily check how many days are left until important dates like exams, anniversaries, vacations, or project deadlines.
Your D-Day information is automatically saved in your browser, so it will be retained when you visit again.
Features
- D-Day Calculation – Automatically calculates days remaining (D-) or elapsed (D+) from target date
- Real-time Countdown – Displays remaining days, hours, minutes, and seconds in real-time
- Detailed Breakdown – Shows total days broken down into weeks and days
- Day of Week – Automatically calculates the day of the week for the target date
- Auto Save – Saves your D-Day to browser storage for automatic loading on next visit
- Copy Result – Copy calculation results as text for easy sharing
Frequently Asked Questions
How is D-Day calculated?
If the target date is today, it shows “D-Day”. If the target is in the future, it shows “D-N” (N days remaining). If it’s in the past, it shows “D+N” (N days elapsed).
Where is the saved D-Day stored?
D-Day information is stored in your browser’s local storage. It will be automatically loaded when you revisit using the same browser.
Can I save multiple D-Days?
Currently, only one D-Day can be saved at a time. When you calculate a new D-Day, it replaces the previous one.