DigiKitDate Difference Calculator
Choose two dates to see the gap in years, months and days, plus total days and weeks.
How is the difference between dates calculated?
The difference between two dates is expressed in two ways. One is the total number of days; the other writes the span as years, months and days. Total days are always exact. The years-months-days form needs a rule because months differ in length: whole months are added to the start date and the remaining days are written as days.
How to use it
- Choose the start and end dates.
- Decide whether you want the end day counted.
- Press Run to see the difference, total days and weeks.
Worked examples
| Start | End | Difference | Total days |
|---|---|---|---|
| 29 Feb 2024 | 16 Oct 2026 | 2 years, 7 months, 17 days | 960 |
| 1 Jan 2026 | 31 Dec 2026 | 0 years, 11 months, 30 days | 364 (365 if the end day is counted) |
| 31 Jan 2026 | 1 Mar 2026 | 0 years, 1 month, 1 day | 29 (30 if the end day is counted) |
In the third example, adding one month to 31 January is clamped to 28 February because February is shorter; the 1 day between 28 February and 1 March is written as the remaining day.
When is it useful?
- Seeing how many days are left on a contract, subscription or warranty.
- Finding the years-months-days form of spans such as age or length of service.
- Finding total days and weeks between a project start and delivery.
Things to keep in mind
- Counting the end day or not changes the result by one day; choose according to the rule in your document.
- Time zones and times of day are not used; only calendar days are compared.
- For legal deadlines and interest calculations check the counting rule of the relevant legislation.
Frequently asked questions
How is the number of days between two dates calculated?
The tool compares the calendar day of the two dates and gives the number of days between them. It also shows the difference in years, months and days.
Is the end day counted?
By default no: 1 January to 2 January is 1 day. If you want to count both days, choose “Count”; the total days increase by one.
What if I enter the dates in reverse?
The tool sorts them automatically and still shows a positive difference.
How is the years, months, days difference found?
Whole months are added to the start date up to the last date that does not pass the end date; the remaining days are written as days. For month-end dates (for example 31 January) the addition is clamped to the last day of the month.