Reckonary / Everyday / Date difference
Days between
Pick two dates and see exactly how far apart they are. The same gap is shown three ways at once — a plain day count, a count of whole weeks, and a years-months-days breakdown — because each answers a different question. The day count is best for deadlines and D-day countdowns, the week count for sprints and pregnancy-style tracking, and the years-months-days form for ages and length of service.
There are two honest ways to express the distance between two dates, and they almost never produce the same-looking number. The first is elapsed days: subtract one date from the other and you get a single count that never changes meaning. From June 1, 2026 to August 15, 2026 is 75 days. Divide by seven and that's 10 whole weeks with 5 days left over.
The second is the calendar breakdown — years, months, and days — which is how people actually describe long spans ("two months and two weeks"). That same June-to-August gap reads as 0 years, 2 months, and 14 days. It is the same span of time, just counted by walking the calendar instead of dividing by seven. This is why the weeks line and the years-months-days line rarely agree: weeks are always exactly seven days, but months are 28, 29, 30, or 31 days long, so the calendar view stretches and shrinks as it moves.
This tool measures the gap between two dates, which is the number of nights, not the number of calendar days you touch. Monday June 29 to Friday July 3, 2026 comes out as 4 days — the four nights in between. If you are counting days you will actually be somewhere, such as a hotel stay or a trip, that 4 is correct for nights but you occupy 5 calendar days, so add one. The rule of thumb: for duration (how long until, how long since), use the number as shown; for inclusive counts (how many days am I here), add one to the day total.
February is where most date math quietly goes wrong, and this is handled for you. February 1 to March 1 is 29 days in a leap year like 2024 but 28 days in 2025, and the calculator returns each correctly because it works from the real calendar rather than assuming a fixed month length. Dates that do not exist, such as February 30, are rejected instead of being silently rolled forward into March, so a typo gives you no answer rather than a wrong one.
Put a date of birth in the first box and today in the second, and the years-months-days line is an exact age the way a doctor's office or a passport form expects it. Someone born May 15, 1990 is 36 years, 1 month, and 15 days old on June 30, 2026 — and the day total, 13,195, is how many days they have been alive. The same approach works for anniversaries, length of employment, or how long a project has been running.
Does the count include both the start and end date?
No. It measures the gap between the two dates, so the result is the number of nights between them rather than the number of calendar days you would land on. If you need the start date counted too, add one day.
Why don't the weeks and the years-months-days add up to the same thing?
They are two different views of the same gap. Weeks split the total days into groups of seven. The years-months-days view follows the calendar, where months are different lengths, so the two presentations rarely line up exactly.
Can I count to a date in the past?
Yes. Order does not matter, so you can put the earlier or later date in either box and still get the distance between them.
How do I work out someone's age with this?
Enter their date of birth as the first date and today as the second. The years-months-days breakdown is their exact age, and the day total is how many days they have been alive.
Last reviewed June 2026. Great for deadlines, anniversaries, and working out an exact age.