Date Calculator
Calculate the difference between two dates or add and subtract days to find a past or future date.
Calculate Date Difference
Date Difference
The day count measures elapsed time and excludes the starting date. Approximate months and years are based on average calendar lengths, not complete calendar months or years.
Add or Subtract Days
Calculated Date
What Is a Date Calculator?
A Date Calculator is a free online tool that helps you determine the number of days between two dates or find a new date by adding or subtracting a chosen number of days.
How to Calculate the Difference Between Two Dates
Select a start date and an end date, then click Calculate Difference. The calculator returns the elapsed number of days, complete weeks, remaining days, and approximate months and years. You can enter the dates in either order; the elapsed difference is shown as a non-negative value.
How to Add or Subtract Days
Choose a starting date, enter a whole number of days, and select Add Days or Subtract Days. The calculator then displays the resulting calendar date. Entering zero returns the starting date.
Does the Date Calculator Account for Leap Years?
Yes. The calculator uses calendar dates, so leap days and months with different lengths are taken into account when calculating date differences and new dates.
When Can a Date Calculator Be Useful?
Use this tool for planning events, tracking project deadlines, checking elapsed time, working out dates for personal schedules, or finding a date a certain number of days before or after an event. For legal, financial, or official deadlines, check whether special rules apply, such as counting the first day or excluding weekends and public holidays.
Frequently Asked Questions
Does the date difference include the start date?
No. The calculator reports elapsed days between the two dates. For example, the difference between 1 January and 2 January is one day. If you need an inclusive count for a schedule, you may need to add one day.
Are the month and year results exact?
They are approximate conversions based on average month and year lengths. The day difference and the complete-week count are based on the actual calendar dates.
Can I calculate a date in the past?
Yes. Select a starting date, choose Subtract Days, and enter the number of days you want to subtract.
Can I calculate a future date?
Yes. Select a starting date, choose Add Days, and enter the number of days to add.
Is this Date Calculator free?
Yes. It is free to use in a modern web browser and does not require an installation.
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