Years, months and days
The main result is the period split into whole years, whole months and the days left over, for example 1 year, 2 months and 5 days. This is how people usually talk about time between dates: age, length of service, the age of a company, or the time since an event.
How the months are counted
The tool counts how many whole months fit between the two dates, moves the start date forward by that many months, and counts the remaining days. For 15 January 2024 to 20 March 2025, 14 whole months from 15 January 2024 is 15 March 2025, and 5 more days reach 20 March 2025. The answer is 1 year, 2 months and 5 days.
Months have different lengths, so a start day that does not exist in a month, such as the 31st, is moved to the last day of that month. 31 January plus one month is the end of February. Other calculators may round this case differently, so two tools can disagree by a day or two at month ends.
Totals in other units
The table shows the same period as complete months, weeks, days, hours, minutes and seconds. Hours, minutes and seconds assume whole days from midnight to midnight, because no times of day are used.
Include the end date
Tick Include the end date to count both the first and the last day. This adds one day to the result. It is useful for periods such as a contract term, where both dates are part of the period.
Which date comes first
If the second date is earlier, the tool swaps the dates and says so. The result is always a positive period.
Related calculators
For a single number of days, use days between dates. For a count in weeks or months only, see weeks between dates and months between dates. Count up from an event with days since. The guide shows how to do the same in Excel and in code.