How many days are between two dates?

Enter both dates; the 'Total days' line is the count from the first midnight to the second. 1 January to 31 December in the same year is 364 — or 365 counting both days.

Does it count the start day and the end day?

The total counts the days crossed, so 1 January to 2 January is 1 day. The line below it adds one for counts that include both ends.

How many weeks are between two dates?

Total days ÷ 7: the page shows whole weeks and the days left over. 972 days is 138 weeks and 6 days.

How many months are between two dates?

The page counts whole calendar months plus the remaining days — 2 years 7 months is 31 months. Because months differ in length, a month is not a fixed number of days.

How many days are in a year?

365, or 366 in a leap year. A year is a leap year when it divides by 4, except century years, which must divide by 400 — so 2000 was a leap year and 2100 will not be. The next is 2028.

How do I count the days since a date?

Put that date first and today second: the total days is the answer. The countdown calculator does the forward version, in weeks and hours as well.

How do I count months between dates in Excel?

=DATEDIF(start, end, "m") gives whole months, matching the months in this page's calendar answer; "d" gives the total days.

Date Difference Calculator: Days, Weeks, Months Between Dates

Years, months and days between two dates, plus total days, weeks and months, counted both ways.

Inputs

Start date

End date

Include CalculateEveryday mark

Difference

2 years, 7 months, 29 days

Total days: 972
Counting both the start and end day: 973
Weeks + days: 138 weeks, 6 days
Total months: 31 months and 29 days
From: Monday, January 1, 2024
To: Sunday, August 30, 2026

Use this calculator on your own site

Free embed

Two lines of HTML, unlimited views
Shows a small CalculateEveryday bar, with a credit link under the calculator

What each Date Difference input means

Start date: The earlier date. If you enter the later one here by mistake, the page swaps them and says so.
End date: The later date. The total counts the days from the start date's midnight to this one's; a second line adds one for counts that include both ends.

Date Difference formula

calendar span = later − earlier in years, months, days (borrowing) · total days = days between the two midnights · inclusive = total + 1

There are two honest answers to 'how long between these dates', and the page gives both. The calendar answer counts whole years, then whole months, then the days left over — borrowing the length of the previous month when the end day is smaller than the start day, the way you would count on a wall calendar. The flat answer counts days: from one midnight to the other, which is what interest, notice periods and countdowns use. If you need to count both the first and the last day — a hotel stay counted in days, or a contract that says 'from and including' — add one; the page shows that figure too. Leap years are handled because the count uses the real calendar.

Date Difference worked example

From 1 January 2024 to 30 August 2026 is 2 years, 7 months and 29 days. As a flat count it is 972 days — 2024 alone has 366 because it is a leap year — which is 138 weeks and 6 days, or 973 days if both the first and last day are counted.

More Date Difference examples

From Sunday 15 March to Friday 2 October 2026: 0 years, 6 months, 17 days on the calendar, or 201 days flat — 28 weeks and 5 days, and 202 days counting both ends.

From 31 January to 28 February 2026 the result is 0 years, 0 months, 28 days: February has no 31st, so no whole month has passed, even though it is the last day of each month.

Where the Date Difference calculator can give the wrong answer

If the end date is before the start date the dates are swapped and the absolute difference shown, with a note.
Month lengths vary, so a 'month' in the calendar answer is not a fixed number of days: 31 January to 28 February is 0 months and 28 days, while 1 February to 1 March is 1 month.
Whether to count the last day depends on the use. A notice period 'of 30 days' usually counts like the flat figure; a stay 'from the 1st to the 5th inclusive' is 5 days.
Times of day are ignored. Use the hours calculator for a span inside one day.

Spotted a mistake? Tell us

Date Difference reference table

Days in each month, and the running total through the year
Month	Days	Day of the year at month end	In a leap year
January	31	31	31
February	28 (29 in a leap year)	59	60
March	31	90	91
April	30	120	121
May	31	151	152
June	30	181	182
July	31	212	213
August	31	243	244
September	30	273	274
October	31	304	305
November	30	334	335
December	31	365	366

Source: The Gregorian calendar

Date Difference FAQ

: Enter both dates; the 'Total days' line is the count from the first midnight to the second. 1 January to 31 December in the same year is 364 — or 365 counting both days.
: The total counts the days crossed, so 1 January to 2 January is 1 day. The line below it adds one for counts that include both ends.
: Total days ÷ 7: the page shows whole weeks and the days left over. 972 days is 138 weeks and 6 days.
: The page counts whole calendar months plus the remaining days — 2 years 7 months is 31 months. Because months differ in length, a month is not a fixed number of days.
: 365, or 366 in a leap year. A year is a leap year when it divides by 4, except century years, which must divide by 400 — so 2000 was a leap year and 2100 will not be. The next is 2028.
: Put that date first and today second: the total days is the answer. The countdown calculator does the forward version, in weeks and hours as well.
: =DATEDIF(start, end, "m") gives whole months, matching the months in this page's calendar answer; "d" gives the total days.