ClockMath

How Many Days Between Two Dates?

Pick two dates for the days between them, plus weeks, months, years and business days. Leap years counted, end date in or out.

Start date
End date
Nov 12, 2026 to Jan 1, 2027: 50 days (7 weeks 1 day; 1 month 20 days; 36 business days)

Not counting the end date. Counting both days: 51 days. 14 of them are Saturdays or Sundays; business days don’t take off public holidays.

Need the hours too? The time duration calculator takes a time of day on each date.

How it works and common questions

Common date spans

  • Jan 1 to Dec 31, 2026 is 364 days, or 365 days counting both dates.
  • Jan 1, 2026 to Jan 1, 2027 is 365 days: 52 weeks 1 day.
  • A year is 365 days, or 366 in a leap year (2028 is the next one).
  • A month is 28 to 31 days: 30.44 on average.
  • Monday to Friday is 4 days apart, and 5 business days counting both.
  • Business days in 2026 has 261 weekdays (Monday to Friday), before public holidays.
  • Jan 31 to Feb 28, 2027 is 28 days, and a whole month: the end of one month to the end of the next.
  • Mar 1 to Jun 1, 2027 is 92 days, exactly 3 months.
  • Feb 1 to Mar 1 is 28 days, or 29 in a leap year like 2028.
  • 100 days is 14 weeks 2 days, a little over 3 months.

How the days are counted

The calculator counts calendar days from the start date up to the end date: the start date counts and the end date doesn’t, so today to tomorrow is 1 day. Tick “Include the end date” to count both, which adds one. Swap the dates and the answer stays the same; it always counts from the earlier date.

The same span is also shown in weeks and days (the days divided by 7), in months and days and in years, months and days, counting whole months from the start date’s day of the month, and in business days, the Mondays to Fridays in it.

Leap years are built in: February has 29 days in 2028 and every fourth year, except century years not divisible by 400 (1900 wasn’t a leap year, 2000 was). Clock changes make no difference, as each date counts as one day. To work a count out on paper, see how to calculate the time between two dates.

Questions

How do I calculate the number of days between two dates?

Pick the start and end dates above and the count appears at once, with weeks, months and business days. By hand: take the days left in the starting month, add the length of each full month in between, then add the end date's day. March 1 to April 15, 2026 is 30 + 15 = 45 days.

Does the count include the start date and the end date?

By default the start date counts and the end date doesn't, which is what "how many days until" means: Monday to Friday is 4 days. Tick "Include the end date" to count both, as for a leave period or an event that runs on both days: Monday to Friday is then 5 days.

How many business days are between two dates?

The answer counts Mondays to Fridays. Monday, November 9 to Friday, November 13, 2026 is 5 business days counting both dates, 4 without the end date. Public holidays aren't taken off, since they differ by country and employer: subtract any that fall in the span.

How do I count the days from today?

Press "From today" over the start date and pick the end date: the answer is the days until it. For the days since a date in the past, pick it as the start date and press "To today" over the end date. Copy link saves both dates, to share or come back to.

How are months counted when the months have different lengths?

A month is counted from the start date to the same date of a later month: March 15 to April 15 is one month. When that date doesn't exist, the month's last day stands in for it, so January 31 to February 28, 2027 is a whole month (28 days), and January 31 to March 1 is 1 month 1 day. The remainder is shown in days.

Do leap years and daylight saving time change the count?

Leap years do, when the span includes February 29: Jan 1, 2028 to Jan 1, 2029 is 366 days, a year later 365. Daylight saving time doesn't: the calculator counts calendar days, so the day the clocks change still counts as one day, even though it is 23 or 25 hours long.

How many weeks are between two dates?

Divide the days by 7: the whole number is the weeks and the remainder is the extra days. 365 days is 52 weeks 1 day. The calculator shows this under "Weeks and days".

How do I calculate days between dates in Excel or Google Sheets?

With the start date in A2 and the end date in B2, =B2-A2 (or =DAYS(B2,A2)) gives the days between them; add 1 to count both dates. =NETWORKDAYS(A2,B2) gives the business days, counting both dates. =DATEDIF(A2,B2,"m") gives whole months, but it counts January 31 to February 28 as 0 months, where this calculator counts a month.

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