Time between dates calculator: get duration in days, hours, and minutes between two dates or times. Add/subtract dates, count business days. Free, instant.
This time duration calculator finds the exact time between two dates or two times. Enter a start and an end — with optional times — and it returns the gap in two forms at once: a human-readable breakdown such as 3 years, 2 months, 17 days and the raw totals in days, hours, minutes, and seconds. Whether you searched for "time between dates," "duration between dates," "days between dates," or "hours between two times," it is the same calculation shown in the unit you need.
To work out how long is between two dates, you subtract the earlier moment from the later one. Doing that by hand is error-prone because months are 28, 29, 30, or 31 days long and years are 365 or 366 days. This tool does the subtraction for you:
"Days between two dates" can mean two different things, and mixing them up is the most common date-math mistake. Calendar days count every day, including weekends and holidays. Business days (also called working days) count only Monday through Friday. For a project that runs Monday March 3 to Friday March 28, the two counts diverge sharply:
| Measure | Value | Use it for |
|---|---|---|
| Calendar days | 25 days | Billing, interest, lease and contract terms |
| Business days | 19 days | SLAs, delivery windows, payroll, deadlines |
| Calendar weeks | 3.57 weeks | Sprint and timeline planning (days ÷ 7) |
Over a typical month the two figures differ by roughly 28%, so always confirm which one a contract or policy means before you commit to a date.
When you need sub-day precision — "how many hours between two times" or "time difference between 9:15 AM and 5:45 PM" — add a time to each date. For a single shift, enter both times on the same date. For an overnight or multi-day span, enter the full start and end timestamps and the calculator carries the math across midnight automatically. The totals strip then reports the elapsed span as total hours, total minutes, and total seconds, so the tool doubles as an hours calculator and an elapsed-time calculator.
February 29 exists in 2000, 2004, 2008, and every fourth year, except century years not divisible by 400 (1900 had no Feb 29; 2000 did). That is why January 1 to December 31 is 364 days in a normal year but 365 days in a leap year. The calculator accounts for leap years automatically — you never have to remember the rule.
When clocks spring forward or fall back, a span measured in wall-clock time can differ from the real elapsed time by an hour. A duration from 1:00 AM to 4:00 AM on the US spring-forward Sunday is 3 hours on the clock but only 2 hours of real elapsed time. This calculator reports true elapsed time, which is the unambiguous, physics-based answer.
The tool runs in your browser local time zone. For a cross-zone span — say a flight from New York to London — convert both endpoints to the same zone (or to UTC) first, then enter them, so the gap is not silently inflated or shrunk by the offset.
A span from Monday to Friday is 4 days exclusive of the start, or 5 days if you count both endpoints. This calculator returns the exclusive duration — the standard definition of elapsed time. If you need an inclusive count (for example, vacation days from Monday through Friday), add 1 to the result.
Pick a mode at the top: Calculate Duration finds the time between two moments, Add Time and Subtract Time shift a date by a quantity, and Convert Units turns any days/hours/minutes/seconds figure into every other unit. Everything runs entirely in your browser — your dates never leave your computer, there is no signup, and the result is instant. Copy any answer to the clipboard with one click.
Enter a start date and end date (with optional times) and the calculator returns the exact duration in years, months, days, hours, minutes, and seconds. It also reports the total in each individual unit — useful when you need "how many days between two dates" rather than the broken-down form.
The tool handles add/subtract operations too: pick a starting moment, choose to add or subtract a quantity, and get the resulting date and time. Common operations like "what date is 90 days from today" or "what time will it be 8 hours and 45 minutes from now" are one click.
You committed to a 45-business-day delivery on a contract dated March 3. Enter March 3 as the start, toggle business days, and add 45 — the result is May 5. Now you know which week to start your QA buffer.
A friend turns 10,000 days old at some point. Enter their birthday as the start and today as the end; the totals row shows the exact day count. (Born January 1, 2000 → 10,000 days lands on May 19, 2027.)
Enter today as the start and the event date as the end. The result tells you both the calendar breakdown ("2 months, 14 days") and the raw count ("76 days"). Use the raw count for countdown widgets and the breakdown for human-readable copy.
Same workflow in reverse. Anniversaries, project kickoffs, last bug-free deploy — anything where you want to say "it has been N days since."
A 62-year-old planning to retire at 65 enters their date of birth as the start and a target retirement date as the end. The breakdown answers "how many years, months, and days from now," and the totals answer "how many paychecks" if you divide by your pay cycle.
Enter the effective date and the termination date. The totals row gives you total days for prorated billing; the breakdown gives you the "X years, Y months" language most contracts use.
Use add/subtract or duration between two times on the same day for a single shift; toggle working-hours mode for a multi-day timesheet that should ignore weekends and after-hours minutes.
Leap years. February 29 exists in 2000, 2004, 2008, ..., 2024, 2028. A duration of "one year" from Feb 29, 2024 lands on Feb 28, 2025 (non-leap) or Mar 1, 2025 depending on convention — this tool uses the Feb 28 convention, which matches how most legal documents and birthdays are handled. January 1 to December 31, 2025 = 364 days. January 1, 2024 to December 31, 2024 = 365 days (leap year, includes Feb 29).
Daylight saving transitions. In the US, clocks jump forward on the second Sunday of March (losing an hour) and fall back on the first Sunday of November (gaining an hour). A duration spanning March 9, 2025 at 1am to March 9, 2025 at 4am is 2 hours in wall-clock time but 3 hours of elapsed real time. This calculator reports elapsed real time — the unambiguous, physics-based answer.
Time-of-day matters. Jan 1 at 11:59pm to Jan 2 at 12:01am is 2 minutes, not 1 day. If you enter only dates with no times, both are treated as midnight and the result is exactly 1 day. Always include times when sub-day precision matters.
Time zone handling. The calculator runs in your local browser time zone. For cross-zone durations (e.g., a flight from JFK to LHR), convert both endpoints to UTC first, then enter them — or use the world clock tool to do the conversion side-by-side.
Inclusive vs. exclusive endpoints. A duration from Monday to Friday is 4 days (exclusive of the start) or 5 days (inclusive of both endpoints). This tool reports exclusive duration — the standard mathematical definition, and what you want for elapsed time. If you need inclusive counts (e.g., "I'm on vacation Mon through Fri, how many vacation days?"), add 1 to the result.
Duration is the elapsed time between two moments. It is not the number of calendar days touched, not the number of midnights crossed, and not the number of weekdays in the range. It is simply: end-time minus start-time, expressed in whatever units you find useful.
That distinction matters because most off-by-one errors in date math come from confusing duration with one of the other counts. "How many days are between Monday and Wednesday?" can legitimately mean 2 (duration), 3 (inclusive count of named days), or 1 (Tuesday is the only day strictly between them). This calculator always returns duration. If you need a different definition, do the small mental adjustment at the end — but start from an unambiguous number.
Enter the earlier date as the start and the later date as the end, then read the days figure in the totals strip. The calculator returns the exact number of days between the two dates — exclusive of the start day — with leap years and varying month lengths handled automatically, so no manual counting is needed.
Add a time to each date (the time field is optional) and the calculator returns the gap in hours, minutes, and seconds. For a single day, enter both times on the same date; for an overnight span, enter full start and end timestamps and it carries the math across midnight. For example, 9:15 AM to 5:45 PM is 8 hours 30 minutes.
Use the business-days option, which counts only Monday through Friday and skips Saturdays and Sundays. Calendar days and business days can differ by about 28% over a month, so business days is the right measure for SLAs, delivery windows, payroll, and project deadlines, while calendar days suit billing and contract terms.
Yes. Leap years (including the century-year exceptions) are handled automatically, so a one-year span lands on the correct date. Durations also reflect true elapsed time across daylight saving transitions, meaning a span over a clock change is reported in real hours rather than wall-clock hours.
The calculator runs in your browser local time zone. For a duration that crosses time zones — such as an international flight — convert both the start and end to the same zone (or to UTC) before entering them, so the result is not skewed by the offset between zones.
Switch to Add Time or Subtract Time, enter a starting date and time, and supply the quantity in days, hours, minutes, or seconds. The calculator returns the resulting date and time, answering questions like “what date is 90 days from today” or “what time will it be 8 hours from now.” Enter 14 days to add two weeks.
Read the total days from the totals strip and divide by 7. For example, 92 days between two dates is about 13.1 weeks. The calculator shows exact days; weeks are simply days divided by 7, and months vary in length so weeks give a steadier planning figure.