How many days until a deadline, a trip or an exam? How long ago did something happen? Pick two dates to count the days between them, along with weeks, months and the number of weekdays (business days).
How days are counted
- By default the start date is counted and the end date is not – the same way you’d count nights in a hotel stay. From 1 March to 10 March is 9 days.
- Choose “Include the end date” if both days count (e.g. a 1–10 March event lasts 10 days).
- Weekdays are Monday to Friday. Public holidays are not removed, because they differ by country.
Handy reference
| Period | Days |
|---|---|
| 1 week | 7 |
| 1 month | 28–31 |
| 1 quarter | 90–92 |
| 1 year | 365 (366 in a leap year) |
| Weekdays in a year | 260 or 261 (262 in rare leap years) |
Common uses
- Countdowns to holidays, weddings and exams.
- Project timelines and contract periods.
- Interest calculations that use actual days.
- Pregnancy, visa stay and probation tracking.
How to count days by hand
- Count the days left in the start month after the start date.
- Add the full months in between using their lengths (Jan 31, Feb 28/29, Mar 31, Apr 30, May 31, Jun 30, Jul 31, Aug 31, Sep 30, Oct 31, Nov 30, Dec 31).
- Add the day number of the end date.
Example: 15 March to 10 June → 16 days left in March + 30 (April) + 31 (May) + 10 = 87 days. Spreadsheets do the same with =B1-A1.
Leap years
A year is a leap year if it is divisible by 4, except century years, which must be divisible by 400. So 2024 and 2028 are leap years, 2100 isn’t, and 2000 was. Leap years add 29 February, which the calculator includes automatically.
Business days and holidays
The weekday count assumes a Monday–Friday week. To get working days, subtract public holidays that fall on weekdays. Some examples of fixed-date holidays:
- United States: New Year’s Day (1 Jan), Independence Day (4 Jul), Veterans Day (11 Nov), Christmas (25 Dec) – plus several Monday holidays.
- Canada: New Year’s Day, Canada Day (1 Jul), Remembrance Day (11 Nov, in most provinces), Christmas and Boxing Day.
- United Kingdom: New Year’s Day, Christmas Day, Boxing Day, plus bank holiday Mondays.
- India: Republic Day (26 Jan), Independence Day (15 Aug), Gandhi Jayanti (2 Oct), plus state and festival holidays.
Popular countdowns
- Days until Christmas or New Year – set today as the start and 25 December or 1 January as the end.
- Days until your birthday or anniversary.
- Days left in a visa, lease or subscription.
- Days since an event – a start date, a habit streak, a sobriety milestone.
Inclusive vs exclusive counting
Many disputes about deadlines come down to whether both the first and last day count. Hotel nights, loan interest and most “days between” questions exclude one end. Event durations, leave applications and medication courses usually include both. When in doubt, check the rule that applies and use the “include end date” option.
Real-life scenarios
- Countdown to Christmas: From 22 October to 25 December 2026 is 64 days – 46 weekdays.
- Project deadline: A project starting 1 November and due 15 December spans 44 days, but only 31 weekdays before holidays.
- Visa stay: Arriving on 3 June and leaving on 28 August is 86 days (87 counting both days) – under a 90-day limit.
Related calculators
- Add days to a date – find a future date
- Age calculator – age on a date
- Notice period calculator – last working day
FAQs
How many days are in a year?
365 in a common year and 366 in a leap year. The average Gregorian year is 365.2425 days.
How many weeks are in a year?
52 weeks and 1 day (52 weeks and 2 days in a leap year).
How do I count only working days excluding holidays?
Take the weekday count and subtract the public holidays that fall on weekdays in your country.
Can I count backwards?
Yes. If the end date is before the start date, the calculator swaps them and tells you.
Need a date that is a set number of days away? Use the add or subtract days calculator.