Days Between Dates Calculator
Enter a start and end date to find how many days, weeks, months and years lie between them. Optionally include the end day when you're counting a span inclusively.
Quick answer: To find the days between two dates, subtract the earlier date from the later one. This calculator counts the exact number of days (leap years included) and also shows weeks, whole months and years.
Working out how many days are between two dates sounds simple, but months of different lengths and leap years make mental arithmetic error-prone. This calculator counts the exact number of days between a start and end date and also expresses the gap in weeks, in whole months and days, and as a decimal number of years. It's handy for deadlines, notice periods, project timelines, holidays and countdowns. To count from a date to today instead, try our age calculator or the countdown calculator for time until a future date.
How the day count works
The basic count is the number of days from the start date to the end date — effectively the number of nights in between. If you want to count both the first and last day, for example when totalling the length of a stay, include the end day and the calculator adds one.
Inclusive count = Days + 1 (both endpoints counted)
Weeks = Days ÷ 7 · Years ≈ Days ÷ 365.25
| Start | End | Days between |
|---|---|---|
| 12 Jul 2026 | 25 Dec 2026 | 166 |
| 1 Jan 2026 | 1 Jan 2027 | 365 |
| 1 Jan 2028 | 1 Jan 2029 | 366 (leap year) |
Exclusive vs inclusive counting
There are two common ways to count a span. The exclusive count — the default here — measures the gap between the dates, so Monday to Friday is four days. The inclusive count treats both endpoints as part of the span, so Monday to Friday becomes five days. Hotel stays and the gap between dates use the exclusive count; counting how many days an event runs, or how many calendar days you'll be away, usually uses the inclusive count.
Months and years between dates
Because months vary in length, "months between" is shown as whole calendar months plus leftover days rather than a rounded figure. The decimal years value divides the total days by 365.25 to average out leap years, which is close enough for most planning. For an exact age-style breakdown from a birth date, use the age calculator instead.