Days Between Dates
Date & TimePick a start date and an end date. You get the number of days between them, the same span in weeks and in years, months and days, and how many of the days are weekdays (Monday to Friday) and weekend days.
Step by step
From October 6, 2026 to January 14, 2027: 100 days
- The start date always counts; the end date only if you include it. End date included: No.
- Result: 100 days, which is 14 weeks and 2 days or 3 months and 8 days.
- Monday to Friday: 72 days; Saturdays and Sundays: 28 days. Holidays are not taken out.
Once every entry is valid, you’ll see each step of the calculation here.
Formula
- start date
- the first day of the span (always counted)
- end date
- the last date (counted only when included)
- days
- number of calendar days in the span
How it works
The calculator counts calendar days the way a day counter does: the start date counts, the end date does not, unless you include it. From Monday to Friday of the same week that gives 4 days, the number of nights or of full days elapsed. With the end date included it is 5, which is what you want when every day of a vacation or a hotel stay counts.
The same span is shown in weeks (whole weeks plus leftover days) and in years, months and days, counted month by month on the real calendar, so leap years and months of 28 to 31 days are handled. The order of the dates does not matter: if the end date comes first, the calculator swaps them.
Weekdays are Monday through Friday inside the counted days. Federal and state holidays are not taken out, because they vary by employer and state; subtract them yourself if you need business days for a deadline. For an exact age from a date of birth, see the age calculator.
The formula
Internally each date is turned into a day number on the Gregorian calendar, and the two numbers are subtracted. Leap days are counted automatically: a span that includes February 29 is one day longer.
A full year between the same dates is 365 days, or 366 when it includes a February 29. A month is not a fixed number of days, which is why the years, months and days figure follows the calendar month by month.
Example
How many days are there from October 6 to Christmas Day 2026?
- Days left in October after the 6th, counting the 6th: 26. November: 30. December up to the 25th, not counting it: 24.
- Total: 26 + 30 + 24 = 80 days, which is 11 weeks and 3 days. Of these, 58 days are weekdays.
From October 6, 2026 to December 25, 2026 there are 80 days, which is 11 weeks and 3 days.
Load this example into the calculatorFrequently asked questions
How do I count the days between two dates?
Subtract the start date from the end date in calendar days. From January 1 to March 1, 2027 that is 31 days of January plus 28 of February, 59 days. Add 1 if both the first and the last day should count.
Should I include the end date?
It depends on the question. For elapsed time, such as how many days until a deadline, leave it out. For a period where every day counts, such as a 7-day vacation from Saturday to Friday, include it to get 7 days instead of 6.
How many weekdays are between two dates?
The calculator shows the Monday to Friday days inside the counted span. A full week always has 5 of them. Holidays are not removed, so for business days subtract any federal or company holidays that fall in the span.
How many days are in a year?
365 days in a common year and 366 in a leap year. Leap years are those divisible by 4, except century years not divisible by 400: 2028 is a leap year, 2100 will not be.
- Gregorian calendar (Wikipedia)
- Leap year (Wikipedia)
- Federal Holidays (U.S. Office of Personnel Management)