D-day Calculator
Calculate days until or since a date
About this tool
D-day Calculator instantly counts the days remaining until or elapsed since a specific date. Use it to track exams, anniversaries, project deadlines, or any important date. It also automatically lists milestone dates like 100, 200, 500, and 1,000 days.
How to use
- Select a target date.
- The number of days remaining (D-day) or elapsed (D+day) from today is displayed.
- Milestone dates such as 100, 200, 500, and 1,000 days are calculated automatically.
FAQ
What is the difference between D-day and D+day?
D-day shows how many days remain until the target date, while D+day shows how many days have passed since it. If the target date is in the future it shows D-day; if in the past, D+day.
How are exam or military discharge countdowns calculated?
Set the exam or discharge date as D-0 and count the remaining days from today. For example, if the exam is 30 days away, it shows D-30.
Does the count include the current day?
By default, the current day (D-0) is not counted. So if the target is tomorrow, it shows D-1. However, for relationship anniversaries, some people count the starting day as day 1 — adjust accordingly.
Results are for reference only. Please verify with official sources