Days Between Dates — count the days
How many days, weeks and months lie between two dates.
Enter a start date and an end date, and this calculator counts the days between dates instantly — leap years, month lengths and calendar quirks all handled. It counts forward too, so any "how long until" question takes one click.
How to use Days Between Dates
Set the earlier date, set the later one, read the number. The only real subtlety is whether the end days count: from Monday to Friday there are four days between, five if you include both ends. A hotel bills you the first way; some rentals count the second. Decide which convention your situation uses before you quote the number to anyone.
For your age in days, put your birth date on one side and today on the other. The total is usually far bigger than intuition expects — a party trick and a mild shock in a single number.
How many days until Christmas?
This is the question the calculator hears most, in every wording — how many days are left, how many are there, how long until Christmas Day. The answer changes at every midnight, which is exactly why no fixed page can print it and a calculator can. Christmas Day falls on December 25 each year: set the start to today, the end to December 25, and you have the count exact to the day. If December 25 has already passed this year, aim at next year's.
Children often prefer the answer in sleeps — nights left rather than days. Happily it is the same number; it just sounds closer.
Other counts worth running
Days until Halloween or New Year — fixed dates, the same trick as Christmas. Days until Easter — it moves every year, so look up this year's date first, then count to it. Deadlines: the number of days remaining is a far more sobering unit than "about a month".
Anniversaries and streaks — days since a quit date, a wedding, a first run. Age in days for a person, a pet, or a sourdough starter that has become part of the family. The days before Christmas pass slowest at age eight and fastest at forty. The calendar denies all responsibility.
What the number does not include
The count is calendar days, plainly. It does not skip weekends, does not know about public holidays, and does not care which country you are in. For business days you would need a different question and a different tool, because the answer depends on a holiday calendar that varies by place and by year.
It also has no opinion about time of day. Dates are whole days here; a start at midnight and a start at eleven at night sit on the same date and produce the same count.
Questions and answers
- How many days are left until Christmas?
- Count from today to December 25 — the calculator does it in one click, and the result drops by one each midnight. After Christmas, point it at December 25 of the coming year.
- Do you count the start day, the end day, or both?
- By convention, days between two dates exclude the ends: Monday to Friday is four. If your situation counts both ends — event days, billing days — add one to the result.
- Are leap years handled?
- Yes. The count follows the real calendar, so February 29 is included whenever it exists. No mental arithmetic about which years get the extra day.