Count the days between two dates — and much more
The Date Difference Calculator tells you how many days there are between two dates and breaks the gap down into years, months and days, weeks and days, hours, minutes and seconds. It also counts how many of those days are weekdays (Monday to Friday) and how many fall on a weekend.
Use it to count down to a holiday, check a notice period, measure a project, see how long ago something happened or work out a contract length. It opens with the days left until next New Year so you can see a result straight away. Nothing is uploaded — the arithmetic runs in your browser.
How to use the Date Difference Calculator
- Pick the Start date and the End date, or press Today next to either one.
- Tick Include end date if both the first and the last day should count — for example the days of a trip or a leave application.
- Tick Add time of day to enter a start and end time and get the exact hours and minutes.
- Read the total in days, the years-months-days breakdown, and the weeks, hours, weekday and weekend counts.
- Use Swap dates to reverse the order, and Copy result to paste the answer into an email or document.
Date Difference Calculator features
Every useful unit
Days, years-months-days, weeks and days, whole months, hours, minutes and seconds from one calculation.
Inclusive or exclusive
Choose whether the end date counts. The difference between the two answers is exactly one day, and the tool says which one you are seeing.
Weekdays and weekends
See how many Monday-to-Friday working days and Saturday-Sunday days the range contains.
Optional time of day
Add start and end times for durations such as 9:00 on Monday to 17:30 on Friday.
Leap years and month lengths
Calendar maths runs on whole dates, so 29 February and 28-, 30- and 31-day months are always counted correctly.
Order doesn’t matter
Enter the dates either way round; a past date gives the time since, a future date the time until.
How the number of days is counted
By default the calculator counts the start date but not the end date — the same convention as spreadsheets, programming languages and most date calculators. From 1 January to 2 January is 1 day. This is the right answer for “how many days until…”, ages, durations and interest periods.
Some questions need both ends counted. A hotel stay from Monday to Friday is 4 nights, but a conference from Monday to Friday is 5 days. Leave applications, school attendance and visa stays usually count every calendar day, including the first and last. Tick Include end date for those; it adds exactly one day.
| From | To | Days (end excluded) | Days (end included) |
|---|---|---|---|
| 1 Jan 2025 | 31 Dec 2025 | 364 | 365 |
| 1 Jan 2024 | 31 Dec 2024 | 365 | 366 (leap year) |
| 1 Feb 2023 | 1 Mar 2023 | 28 | 29 |
| 15 Aug 2025 | 15 Aug 2026 | 365 | 366 |
Why months and years are not fixed lengths
Days and weeks are exact units, but a month can be 28, 29, 30 or 31 days long and a year 365 or 366 days. So the years-months-days breakdown counts whole calendar months from the start date, then the remaining days. From 31 January 2023 to 1 March 2023 is 1 month and 1 day: one month after 31 January lands on 28 February (February has no 31st, so it is clamped to the last day), and one more day reaches 1 March.
The “Months and days” total uses the same rule. Avoid converting days into months by dividing by 30 or 30.44 when accuracy matters — the answer will drift by a day or two depending on which months the range covers. To move a date forward by a number of months instead, use the Date Calculator; for someone’s age, the Age Calculator applies the same method, and the Anniversary Calculator counts years married and the next milestones.
Weekdays, holidays and time zones
The weekday count includes every Monday to Friday in the range and does not remove public holidays, which differ by country, state and employer. Subtract your local holidays from the weekday total, or use the Business Days Calculator to add a holiday list.
With time of day switched on, each day counts as 24 hours. If a daylight-saving change happens between the two dates, the real elapsed time is one hour shorter (in spring) or longer (in autumn) than shown. The date-only results are never affected by daylight saving.
Date Difference Calculator FAQ
How do I calculate the number of days between two dates?
Enter both dates in the date difference calculator. It subtracts the earlier date from the later one, counting the start date but not the end date. Tick “Include end date” to count both.
How many days are there in a year?
A common year has 365 days and a leap year has 366. Leap years occur every four years, except century years that are not divisible by 400 — so 2000 was a leap year but 2100 will not be.
How many weeks are between two dates?
Divide the number of days by 7. The calculator shows whole weeks plus leftover days, for example 365 days = 52 weeks and 1 day.
Does it count weekends and holidays?
The total counts every calendar day. Separately, it shows how many of those days are weekdays and how many are Saturdays or Sundays. Public holidays are not removed automatically.
Why is my answer one day different from another calculator?
Almost always because one counts the end date and the other does not. Toggle “Include end date” to see both answers.
Can I calculate the time between two dates and times?
Yes. Tick “Add time of day”, then set a start time and an end time. The result includes hours and minutes, and the totals in hours, minutes and seconds update too.