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Days between dates calculator

Pick two dates to count the days between them, and see the same span in weeks, months and years. Turn on business days to leave out weekends and public holidays.

The end date isn’t counted, like a duration: Monday to Friday is 4 days. That’s the usual answer to “how many days until…”.

Leaves out Saturdays, Sundays and the public holidays you choose.

Days between the dates
—
Pick a start date and an end date.
  • Nothing is uploaded
  • Free, no sign-up
  • Works on phone and desktop

How to count the days between two dates

  1. 1

    Pick a start date and an end date. Both start as today and 30 days from today; the swap button flips them.

  2. 2

    Decide whether to include the end date. Leave it off for "how many days until", turn it on to count every day of a period.

  3. 3

    Want working days only? Turn on Count business days and choose US federal holidays or UK bank holidays.

  4. 4

    Read the total, plus the same span in weeks, months, years and hours. Copy the result or a link that reopens it.

Features

  • With or without the end date

    October 1, 2026 to October 31, 2026 is 30 days, or 31 when both ends count. One switch, explained in plain words.

  • Business days and holidays

    Leave out weekends plus US federal or UK bank holidays, with every holiday in the range listed by date.

  • Weeks, months and years

    See the span as weeks and days, months and days, and years, months and days, counted the way people count ages.

  • Hours, minutes and seconds

    The same span in smaller units: 30 days is 720 hours or 2,592,000 seconds.

Inclusive or exclusive: counting the end date

There are two honest answers to "how many days from October 1, 2026 to October 31, 2026?" Counted as a duration, the way you'd count the days you have to wait, it's 30 days. Counted inclusively, with both the first and last day, it's 31, one for every date on the calendar page. The calculator leaves the end date out unless you switch it on.

  • Leave it off for countdowns and durations: days until a trip, a due date or a deadline, days since an event, or an age in days.
  • Turn it on when every day of a period counts: the days of a trip, a conference, a leave request or "working days in October".

Calendar days vs business days

Calendar days are every day, weekends included. Business days leave out Saturdays, Sundays and public holidays. In October 2026, there are 31 calendar days, 9 weekend days and one US federal holiday (Columbus Day, on October 12), which leaves 21 business days. The same month has 22 in England and Wales. Turn on Count business days and the calculator lists every holiday it left out, so you can check it against your employer's calendar. For a deeper look at working days, see the business days calculator.

Months of different lengths and leap years

The total in days is always exact. Months and years need a rule, because months run from 28 to 31 days. The calculator counts whole months from the start date first, then the days left over, the same way people count ages and contract terms:

  • January 31, 2026 to March 1, 2026 is 1 month and 1 day.
  • January 31, 2026 to February 28, 2026 is 1 month: February has no 31st, so its last day stands in.
  • February 1 to March 1 is 28 days in 2026 but 29 days in 2028, a leap year.
  • March 1, 2026 to March 1, 2027 is 365 days, while March 1, 2027 to March 1, 2028 is 366, because it includes February 29, 2028.
MonthDaysMonthDays
January31July31
February28 (29 in a leap year)August31
March31September30
April30October31
May31November30
June30December31

Common uses

  • Age in days: someone born on June 15, 1990 was 13,283 days old on October 27, 2026.
  • Contract terms and notice periods: notice given on November 2, 2026 for November 30, 2026 is 28 days. Contracts differ on whether the day notice is given counts, so check the wording.
  • Project schedules: count the business days left before a launch, or the weeks between two milestones.
  • School and leave planning: September 1, 2026 to June 1, 2027 is 273 days, or 9 months.

The hours, minutes and seconds assume 24-hour days. A daylight saving change in the range adds or takes away one hour in most of the US and the UK. To find a date rather than count the days to one, use the date calculator or the days from today calculator. For clock times, try the hours calculator.

Frequently asked questions

How do I count the days between two dates?

Subtract the earlier date from the later one, counting calendar days. From October 1, 2026 to October 31, 2026 is 30 days. That's the number of days you'd wait, so the end date isn't counted. If you need every day of the period, both ends included, it's 31.

Should I include the end date?

It depends on the question. "How many days until my vacation?" doesn't count the end date: Monday to Friday is 4 days away. "How many days is my vacation?" counts both the first and last day, so Monday to Friday is 5 days. Working-day counts, like Excel's NETWORKDAYS, usually include both ends.

How many business days are between two dates?

Turn on "Count business days". Weekends and the public holidays you choose are left out. For example, October 2026 has 31 days, 9 of them on weekends, and 21 working days once Columbus Day (a US federal holiday) is taken out. In England and Wales, with no bank holiday that month, it's 22.

How do I calculate my age in days?

Enter your birth date as the start date and today as the end date. Someone born on June 15, 1990 was 13,283 days old on October 27, 2026, which is 36 years, 4 months and 12 days.

How many days are in a year?

365, or 366 in a leap year, when February has 29 days. Leap years come every 4 years, except century years that can't be divided by 400: 2000 was a leap year, but 2100 won't be. That's why March 1, 2027 to March 1, 2028 is 366 days.

Why does January 31 to February 28 count as one month?

Because February has no 31st, its last day stands in for it. Counting a month from January 31 lands on February 28, so the span is 1 month, the same as from January 28 (1 month). The total in days still differs, and the day count is always exact.

What if the end date is before the start date?

You still get the number of days, and the calculator tells you the end date comes first, so the count runs back in time. The swap button puts the dates in order.

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