Date Calculator: Duration Difference, Add and Subtract

Start Date (dd/mm/yyyy):
End Date (dd/mm/yyyy):


This tool calculates the number of days, months and years between two dates, adds or subtracts days, weeks, months and years from a given date.

Table of contents:

How to calculate duration between two dates?

Enter the start date and end date, then click the "Subtract" button to find how many days, months and years between the dates.

How to calculate a target date?

Enter a start date and the number of years, months, weeks and days then click "Add" button to find the end date.

What is the purpose of the Gregorian calendar?

The Gregorian calendar is the calendar in current use in the Western world, both as the civil and Christian ecclesiastical calendar. Instituted by Pope Gregory XIII in 1582, the calendar has 365 days with an extra day every four years (the leap year) except in years divisible by 100 but not divisible by 400.

Which countries do not use the Gregorian calendar?

Civil calendars worldwide: The majority of countries in the world use the Gregorian calendar as their sole civil calendar. Countries which do not use the Gregorian calendar are Afghanistan and Iran, which use the Solar Hijri calendar, Ethiopia (Ethiopian calendar) and Nepal (Vikram Samvat).