D-Day Calculator
Find out exactly how many days, weeks, months, and years lie between two dates, or track the D-day countdown to an important date. Calculations use the real calendar and run instantly in your browser.
How to use
- Choose a mode: days between two dates, or D-day countdown.
- For 'days between', pick a start and an end date.
- For 'D-day', pick a target date.
- Read the total in days and weeks.
- See the exact calendar breakdown in years, months, and days.
Frequently asked questions
- How is the D-day number calculated?
- It's the number of days from today to the target. The day itself is D-Day, future dates show D-minus, past dates show D-plus.
- Are months and years exact?
- Yes. The breakdown uses the actual calendar (accounting for different month lengths and leap years), not a rough average.
- Is my data saved?
- Your dates are stored locally in your browser so they're there when you return, but nothing is uploaded.
- Which timezone is used?
- Dates are compared by calendar day using your device's local date, so there are no timezone surprises.
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