What is D-day Countdown?
D-day Countdown is an online tool that lets you track the days remaining until important dates in real-time. Register events like exams, birthdays, anniversaries, travel dates, and project deadlines to manage your D-days at a glance.
Future events are displayed as D-N (days remaining), today's events as D-Day, and past events as D+N (days elapsed). With real-time countdown showing days, hours, minutes, and seconds, you can track exact remaining time for up to 20 simultaneous events.
Key Features
Multi-Event Management
Register and manage up to 20 D-day events simultaneously. Sort by date or name for efficient tracking.
Real-time Countdown
Beyond just day counts, get real-time countdown in hours, minutes, and seconds for precise time tracking.
6 Categories
Organize events into 6 categories: General, Birthday, Anniversary, Exam, Travel, and Work for systematic management.
Auto Save
All events are automatically saved in your browser's localStorage, so your data persists even after closing the page.
Copy & Share
Copy D-day information as text to easily share via messenger or social media.
How to Use
- Add Event: Click 'Add Event' and enter the title, target date, and category. You can optionally add a memo.
- Choose Category: Select from General, Birthday, Anniversary, Exam, Travel, or Work to categorize your event.
- Track in Real-time: Registered events are automatically calculated with real-time countdown. Displayed as D-N (future), D-Day (today), or D+N (past).
- Manage & Share: Edit or delete events, and copy as text to share. Use sorting for efficient management.
Use Cases
Exam Preparation
Register D-days for college entrance exams, certifications, and professional tests to plan your study schedule with real-time remaining time.
Anniversary Management
Register important dates like relationship anniversaries, wedding anniversaries, and family birthdays so you never miss a special day.
Travel Planning
Add excitement with a countdown to your departure date and systematically manage your preparation timeline.
Project Deadlines
Register work project deadlines, presentation dates, and submission dates to effectively manage your timelines.
Frequently Asked Questions (FAQ)
How many D-days can I register?
You can register and manage up to 20 D-day events simultaneously.
Are registered D-days saved?
Yes, all D-day events are automatically saved in your browser's localStorage. They persist between visits on the same device and browser.
Does it work on mobile devices?
Yes, with responsive design it works perfectly on smartphones and tablets.
Is this service free?
Yes, completely free with no registration or installation required.
Can I see past D-days?
Yes, past dates are displayed as D+N showing how many days have passed. They are not automatically deleted, so you can check anniversaries.
Privacy Notice
This D-day countdown tool stores all data only in your browser's localStorage and does not transmit anything to a server. Event information (title, date, category, memo) is processed only on your device.