Use of
- in the tab. D-day / Date difference / Date Add Select the desired mode.
- D-day is: Select the target date and press Calculate to show today’s D-n (South) · D+n (South) and the target day, weekdays, and monthly exchange rate.
- The date car.: If you enter two dates and specify whether to include the start date, you will see the exchange between days and weeks, months and years.
- and more dates.If you add a reference date or enter a number of days, the resulting date and day will be displayed, for example, you can see how many days are from today to 100 days later.
D-day calculation method
D-day refers to the day of the target day, and the date ahead of which is left to the target day or the number of days before.
| Signed | Meaning of |
|---|---|
| D-7 | Goal 7 days ago. |
| D-1 | The goal a day ago. |
| D-day (D-0) | Target for the day. |
| D+1 | Goal the next day. |
The calculation is done by matching both dates to midnight (0:00), dividing the millisecond difference by a day (86,400,000 milliseconds) and rounding it. The view ignores and compares only the dates, so whether you count in the morning or in the night, the result is the same.
Difference from the beginning.
Even the same two dates, the results vary a day depending on whether the first day is counted. From today to tomorrow, the interval is one day, but the first day is included in two days. In the calculation of the period in the civil law, the first day calculation method is generally used without the first day.
| Method of calculation. | Today is tomorrow. | If used by |
|---|---|---|
| Beginning of Missing. | 1 day | Date interval, D-day, number of days of stay (several nights) |
| Starting from the beginning (including) | 2nd day | Working hours, package days, entire travel schedule (several days) |
Month of Month of Month.
Because months and years vary in length from month to month, it is not possible to divide them precisely, so 1 month = approximately 30.44 days (365.25 days÷12), 1 year = approximately 365.25 days, and 1 year = approximately 365.25 days. nearbyProvide it for use.
Knowing good information.
- Prepared for test.Set the test day as your target day to pre-check D-100, D-50, and D-30 and divide the section of your study plan.
- by Countdown.: If you insert the overall scheduled date, the remaining date will come out right away. Calculation of day.It is more convenient.
- After the goal. It automatically changes to D+n, so you can also add the project start date to count the number of days in progress.
- Contract for Repayment.If you add a number of days like the base date and 14, 30 in the Date Add mode, you will be able to know the date and day of the deadline right away.
- Annual anniversary, which starts as one day as 100 days and 1000 days. Calculation of anniversary.The D+ and Korean symbols are different for a day.
This page is based on the year 2026, and the month/year conversion is based on the average near value. All calculations are made only in the browser and the dates entered are not stored.
Frequently asked questions.
D1 was the day before.
D-1 is the day before the target day. The target day is marked as D-day (D-0) and the next day is marked as D+1, D+2.
When do I check the "Including Start Date" in the Date Difference?
When you break the interval of two dates, such as the number of accommodation days, you choose a default (today ~ tomorrow = 1 day), and when you have to count the first day as a day, such as the number of working days and agreement days, you choose including (today ~ tomorrow = 2 days).
Is the monthly calculation accurate?
The average month is 30.44 days (365.25 days ÷12), and the average year is divided by 365.25 days.
Is time reflected in the calculation?
No. All calculations compare dates only on the basis of noon (00:00).
What if I add a number to the date?
For example, typing -30 shows the date and day before the 30th day of the basis.