Find the exact time between two dates: total days, weeks, and hours, a years, months, and days breakdown, and the count of business days that fall between them.
Runs entirely in your browser — your data never leaves your device.
How to use Date Difference Calculator
What it does & when you need it
How many days until the deadline? How long has the project been running? How many
working days are there between two dates? This calculator answers all three at once.
Give it a start and end date and it reports the total span in hours, days, and
weeks, a precise years-months-days breakdown, and the number of business days that
fall between them. The difference is always absolute, so it works equally well for
counting up from a past date or down to a future one. Everything is computed
locally in your browser.
How to use
Pick a Start date and an End date with the two date fields.
Read the breakdown: the calendar years, months, and days, plus running totals and
the business-day count.
The order does not matter — swap the dates and the totals are identical.
Press Copy result (or Ctrl/Cmd + Enter) to copy the full breakdown.
Things worth knowing
Real calendar maths. The years, months, and days figure counts actual calendar
units, borrowing from the correct preceding month, so leap years are handled
properly. From 28 February 2024 to 1 March 2024 is two days, because 2024 has a
29 February.
What a business day means here. Every weekday — Monday through Friday — in the
span, counting the days after the start up to and including the end. Weekends are
skipped, but public holidays vary by country and are not deducted. A seven-day
Monday-to-Monday span therefore contains five business days.
Times are optional. A plain YYYY-MM-DD date works, but you can also pass a
full ISO date-time and the total-hours figure reflects it. For a single birth date
against today, use the age calculator; to turn a raw span
of seconds into words, try the duration formatter.
Examples
A full calendar year
2024-01-01 to 2024-12-31
A leap year: 365 days from the 1st to the 31st, with the business-day count alongside.
Across a leap February
2024-02-28 to 2024-03-01
Two days, because 2024 has a 29 February between the endpoints.
One working week
2024-01-01 to 2024-01-08
Seven calendar days but only five business days, Monday to Monday.
Frequently asked questions
How are the years, months, and days worked out?+
The tool counts calendar units rather than fixed averages: whole years first, then the leftover whole months, then the remaining days, borrowing from the actual preceding month when needed. Because months vary in length and February gains a day in leap years, this gives a true breakdown — 28 Feb 2024 to 1 Mar 2024 is 2 days, since 2024 has a 29 February.
What counts as a business day?+
Every weekday, Monday through Friday, in the span — specifically the days after the start date up to and including the end date. Weekends are skipped and public holidays, which vary by country, are not deducted. So a Monday-to-the-next-Monday span of seven calendar days contains five business days.
Does the order of the two dates matter?+
No. The difference is always absolute, so swapping the start and end dates gives the same totals. This makes it just as useful for counting down to a future deadline as for measuring how long ago something happened.
Can I include a time of day, not just a date?+
Yes. Alongside a plain YYYY-MM-DD date you can pass a full ISO date-time such as 2024-01-01T09:30, and the total-hours figure will reflect it. The years, months, and days breakdown and the business-day count work on whole calendar days.
Is anything sent to a server?+
No. Every calculation runs locally in your browser, so the dates you enter never leave your device and the tool keeps working offline once the page has loaded.