How to use the calculator
- Enter the start date and the end date. Their order doesn't matter.
- Choose whether to include the end date (adds one day).
- Press Calculate to get the total days, the same period in years, months, weeks and hours, and a weekday/weekend breakdown.
Days until popular dates
Counted from today, October 18, 2026:
| Event | Date | Days to go |
|---|---|---|
| Halloween | Saturday, October 31, 2026 | 13 |
| Christmas Day | Friday, December 25, 2026 | 68 |
| New Year's Eve | Thursday, December 31, 2026 | 74 |
| New Year's Day | Friday, January 1, 2027 | 75 |
| Valentine's Day | Sunday, February 14, 2027 | 119 |
Is the end date included?
By default the start date is counted and the end date is not – the same as counting nights in a hotel or days until an event. Include the end date when both the first and last day matter, such as leave or event days.
| From | To | Without end date | With end date |
|---|---|---|---|
| Monday | Friday (same week) | 4 | 5 |
| March 1, 2026 | March 31, 2026 | 30 | 31 |
| January 1, 2026 | December 31, 2026 | 364 | 365 |
| January 1, 2028 | December 31, 2028 | 365 | 366 |
How to count the days by hand
- Count the days left in the start month after the start date.
- Add the full length of every month in between.
- Add the day number of the end date.
- Rest of June: 30 − 15 = 15 days
- All of July: 31 days
- August 1–29: 29 days
Total: 15 + 31 + 29 = 75 days, which is 2 months and 14 days.
Leap years
A leap year has 366 days instead of 365. The rule:
- Years divisible by 4 are leap years (2024, 2028) …
- … except years divisible by 100 (1900, 2100) …
- … unless they are also divisible by 400 (2000, 2400).
The calculator counts real calendar days, so any February 29 inside your range is included automatically.
Count days in Excel or Google Sheets
| You want | Formula (start in A2, end in B2) |
|---|---|
| Days between | =B2 - A2 or =DAYS(B2, A2) |
| Including the end date | =B2 - A2 + 1 |
| Weekdays (Mon–Fri) | =NETWORKDAYS(A2, B2) |
| Whole months | =DATEDIF(A2, B2, "M") |
Frequently asked questions
How many days are there in a year?
365 in a common year and 366 in a leap year. Across the 400-year Gregorian cycle the average is 365.2425 days.
Is the end date included?
Not by default: the start date counts and the end date does not. Set “Include End Date” to Yes to count both, which adds one day.
What if I enter the dates in the wrong order?
They are swapped automatically, so the answer is always a positive number of days. The summary tells you when this happens.
How many weeks are between two dates?
Divide the days by 7. The result shows it for you as weeks and leftover days, for example 68 days = 9 weeks 5 days.
How many weekdays are between two dates?
The breakdown below the calculator lists Monday–Friday days and weekend days. To leave out holidays too, use the Business Days Calculator.