31Free calculator

Days between dates calculator

How many days until a holiday, a deadline or a birthday? Pick two dates to see the number of days, weeks, weekdays and hours between them.

Duration
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Weeks
Months (average)
Weekdays (Mon–Fri)
Hours

Calculated instantly in your browser — nothing you enter is sent or stored.

Embed this calculator on your website

Free for blogs and websites: copy the code and paste it into your page (in WordPress, use a “Custom HTML” block). It works on phones and desktops, and the height adjusts automatically.

Preview

How to use the calculator

  1. Choose a start date and an end date. You can also use the quick buttons (+7, +30, +90 days or until Christmas).
  2. Tick Include the end date if both the first and last day should count, for example for a hotel booking or a holiday that includes both days.

The result shows the total days and the same period in weeks and days, in months, as weekdays (Monday–Friday) and in hours. If the end date is before the start date, the result is negative.

How the days are counted

The calculator counts the number of midnights between the two dates. So 1 March to 2 March is 1 day. With "Include the end date" ticked, it adds one, so the same range counts as 2 days, both days included.

days = (end date − start date) ÷ 86,400 seconds (+1 if the end date is included)

Dates are compared in UTC, so changes to daylight saving time never make a day count as 23 or 25 hours.

Worked examples

From 1 January to 31 December

In a normal year that is 364 days between the dates, or 365 days with the end date included. In a leap year it is 365 or 366.

A 90-day visa limit

If you arrive on 10 June and the stay counts both arrival and departure days, the 90th day is 7 September. Tick "Include end date" and adjust the end date until the result shows 90.

Weeks of pregnancy or training plans

Enter the start date and today. The weeks and days line shows, for example, "11 weeks, 3 days".

Weekdays vs working days

The weekday count here simply skips Saturdays and Sundays. For a count that also removes public holidays, or for a different working week, use the working days calculator.

Frequently asked questions

Does the calculator include the start and end date?
By default it counts the days between the two dates, which includes the start date but not the end date. Tick “Include the end date” to count both.
How many days are left until Christmas?
Click “Until Christmas” and the calculator counts from today to 25 December. The home page also shows a live countdown.
How are leap years handled?
Automatically. 29 February is counted whenever it falls inside your period.
Why is a month shown as a decimal?
Months have different lengths, so the calculator divides by the average month length (30.44 days). For exact calendar months, use the age calculator, which counts whole months.

Last reviewed: November 13, 2026

Results are estimates for general information only and are not financial, tax, medical or legal advice. Check important figures with a qualified professional.