Counting days by hand on a calendar is error-prone because months have 28 to 31 days and leap years add 29 February. Whether to include the end date depends on the question: a hotel stay from the 1st to the 5th is 4 nights, while a festival from the 1st to the 5th lasts 5 days.
How to use the Days Between Dates Calculator
- Start date
- End date
- Include end date
- Count
- Public holidays to exclude
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the start and end dates, decide whether to count the end date, and optionally exclude weekends and a number of public holidays.
Tips
- Check whether the end date should be included – event durations usually include it, elapsed time does not.
- Months have 28–31 days, so “one month” is counted by calendar date, not as 30 days.
- Use 24-hour time or set AM/PM carefully when entering clock times.
- Time zones and daylight-saving changes are not applied unless the calculator says so.
Common mistakes to avoid
- Counting a 30-day month when a calendar month is meant (or the reverse).
- Forgetting leap years when counting days across February.
- Mixing decimal hours (7.5 h) with clock time (7:30).
Inputs explained
| Field | What to enter |
|---|---|
| Start date | A date |
| End date | A date |
| Include end date | Choose one: No, Yes (+1 day) |
| Count | Choose one: All days, Working days only (Mon–Fri) |
| Public holidays to exclude | A number |
What each result means
- Full weeks = sign([Calendar days])×floor(abs([Calendar days])÷7)
- and days = sign([Calendar days])×mod(abs([Calendar days]), 7)
- Full months = monthsbetween([Start date], [End date])
- Years = [Calendar days]÷365.2425
- Hours = [Calendar days]×24
- Weekend days = [Calendar days] – workdays([Start date], [End date] + [Include end date])
Formula
Days = end date − start date (+ 1 if the end date is included)Working days = days that fall Monday–Friday − holidaysWeeks = days ÷ 7Worked example
Inputs — Start date: 2026-10-25; End date: 2027-02-02; Include end date: No; Count: All days; Public holidays to exclude: 0.
Results — Days between = 100; Full weeks = 14; and days = 2; Full months = 3; Years = 0.274; Hours = 2,400; Weekend days = 29.
Frequently asked questions
How many days between two dates?
Subtract the earlier date from the later one; add 1 if you count both the first and the last day.
Should I include the end date?
Include it when counting days of an event (both days are used); exclude it when counting nights or elapsed time.
How many working days are in a year?
About 260 weekdays, minus public holidays – typically 250–255.
What formula does the Days Between Dates Calculator use?
Days = end date − start date (+ 1 if the end date is included).