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Date Calculator

Find calendar days between dates or add and subtract a whole number of days from a date.

Runs in your browserFree · No account required

Calculate calendar days or move a date

Find the signed number of calendar days between two dates, or add and subtract a whole number of days. The calculation treats date inputs as calendar dates, not times, so daylight-saving clock changes do not add or remove a day.

1

Enter your details

Change the values, then run the tool.

Data handling

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How it works

Date Calculator: a practical guide

A date calculator helps answer calendar questions without converting dates into timestamps by hand. Use it to find the number of whole calendar days between two dates, or to move forward or backward by a chosen number of days. It treats dates as calendar values, so daylight-saving changes and time zones do not alter the answer.

  1. STEP 01

    Choose whether to compare two dates or add and subtract days.

  2. STEP 02

    Enter valid dates, or enter a whole-number day offset.

  3. STEP 03

    Calculate and review the signed direction when the end date comes before the start date.

What this tool does and its limits

The days-between result is a signed difference: an end date earlier than the start produces a negative number. The end date is not counted as an extra inclusive day. Add/subtract mode uses whole calendar days. Date-only calculations do not account for business days, holidays, or time of day.

Processing happens in your browser. The selected file or entered values are not uploaded to Got A Tool or saved by this tool.

Frequently asked questions

Are both dates included in the count?
No. The calculator returns the difference between the calendar dates; it does not add an inclusive day.
Why does it ignore time zones?
The inputs are dates, not moments in time. Treating them as UTC calendar dates avoids daylight-saving shifts changing a day count.
Can I count business days or holidays?
No. This version counts calendar days and does not include a holiday or workday calendar.
Can I add a negative number of days?
Yes. A negative whole-number offset moves the result backward from the starting date.

Keep working

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