Counting the days between two dates
The simplest way to count is to subtract the earlier date from the later one. Between 1 January and 25 December of the same year there are 358 days. This calculator does that for you, and also shows the same gap as weeks and days, and as years, months and days. If you enter the dates the wrong way round, it swaps them rather than showing a negative number. Dates are treated as calendar dates in UTC, so daylight-saving changes never add or remove a day.
Inclusive or exclusive?
Whether you count the end date makes a one-day difference, and the right choice depends on the question. "How many days until my holiday?" normally excludes today and counts the days in between. "How many days will I be away if I leave on the 5th and return on the 9th?" is often answered by counting both the first and last day, which gives five days. Tick the checkbox to include the end date. Contracts, rental agreements and deadlines can have their own counting rules, so read the wording carefully when something important depends on it.
Weekdays and working days
The weekday figure counts Monday to Friday between your two dates, using the same inclusive or exclusive setting. It does not remove public holidays, because holidays differ by country, region and employer. For a rough estimate of working days that is usually close enough. For payroll or legal deadlines, subtract the holidays that apply to you from the result.
Adding and subtracting days
The second tool answers questions such as "what date is 90 days from today?", "when does a 30-day return window end?" or "what was the date 100 days ago?". Enter a start date, choose add or subtract and type the number of days. You get the resulting date together with the day of the week, which is handy for checking that a deadline does not land on a weekend.
Leap years
A leap year has 366 days instead of 365, with an extra day on 29 February. The rule is that a year divisible by 4 is a leap year, except years divisible by 100, unless they are also divisible by 400. So 2024 and 2028 are leap years, 1900 and 2100 are not, and 2000 was. The calculator applies this automatically, which is why the gap from 1 January 2024 to 1 January 2025 is 366 days, but 365 days for the following year.
Common uses
- Countdowns to holidays, exams, weddings and product launches.
- Project planning, including how many working days a task window gives you.
- Checking notice periods, trial lengths, warranties and return windows.
- Tracking streaks, habits or the time since an event.
Everything runs in your browser and none of the dates you enter are sent or stored.