Count days between dates or shift a date. This free date calculator finds the days (and weeks) between two dates, or adds/subtracts days to land on a new date, showing the resulting weekday.
Calculate
Pick two dates to count the days (and weeks) between them. The end date can be earlier than the start — the result will simply be negative.
days
Pick a date, then add or subtract a number of days to find the resulting date.
Days between
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Enter dates
Weeks
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Weeks & days
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Including end day
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Day of week
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Days between counts the nights from the start date to the end date. “Including the end day” adds one, which is how you’d count inclusive spans like a holiday or hotel stay differently from nights.
Use this free date calculator to count the days between two dates, or to add or subtract days from a date. It also shows weeks, the resulting weekday, and inclusive spans.
What this date calculator does
A date calculator has two modes: find the number of days between two dates, or add/subtract days from a starting date to land on a new one. It handles leap years and month lengths automatically.
How days between dates are counted
Days between = end date − start date (in whole days)
Including the end day = days between + 1
From 1 January 2025 to 31 December 2025 is 364 days. Counting inclusively (both endpoints) gives 365 — useful for spans like holidays where you count every day, not just the nights.
Adding and subtracting dates
Example
Result
13 Jun 2025 + 90 days
11 Sep 2025
13 Jun 2025 − 30 days
14 May 2025
1 Jan 2025 + 7 days
8 Jan 2025
Date vs time vs hours
Use this date calculator for calendar days. For lengths of time in hours/minutes/seconds use the Time Calculator, and for hours worked between a clock-in and clock-out use the Hours Calculator.
How to use the date calculator
Choose “days between” or “add / subtract.”
Enter your date(s) — and a number of days for add/subtract.
Read the result, weeks and weekday.
Date Calculator FAQ
How do I find the number of days between two dates?
Choose "days between," pick a start and end date, and the calculator counts the whole days — for example, 364 days from 1 Jan 2025 to 31 Dec 2025.
How do I add days to a date?
Switch to "add / subtract," pick a date, choose add, and enter the number of days. For instance, 13 June 2025 plus 90 days is 11 September 2025.
What does "including the end day" mean?
It adds one to the count, so you're counting both endpoints. That's useful for inclusive spans like a holiday, versus counting only the nights.
Does it handle leap years?
Yes. It uses real calendar dates, so leap days and different month lengths are handled automatically.
Can the end date be before the start date?
Yes. The result is simply shown as a negative number of days.
Is the date calculator free?
Yes, this date calculator is completely free, needs no sign-up, and gives instant results in your browser.
