Date Difference Calculator — Days, Hours & Time Between Dates
Find the difference between two dates in years, months and days, plus total days, weeks, hours, minutes and seconds. Add optional times to get the exact hours between two times.
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Just need the hours between two clock times on the same day (e.g. a work shift)?
Open the Time Duration CalculatorAdd or subtract from a date
How to calculate the difference between two dates
Enter two dates
In any order — the calculator handles both directions, or use Swap to reorder them.
Add times for hour precision
Optional start and end times switch the totals to exact elapsed hours, minutes and seconds.
Read the full breakdown
Calendar difference, total days/weeks/hours/minutes/seconds, and weekday/weekend counts.
Hours between two dates
Without times, the calculator treats each date as midnight, so the hours figure is simply the number of elapsed days multiplied by 24. Add a start time and end time and it switches to exact elapsed time: the whole days between the dates, plus the leftover hours and minutes from the clock times. The same span is then shown three ways — total hours, total minutes and total seconds — so you can paste whichever unit a form or timesheet asks for.
Calendar difference vs elapsed time
These are two different questions and they do not convert with a fixed formula:
Calendar difference
"2 years, 3 months, 5 days." Counted the way a person counts on a calendar, borrowing across months of different lengths and leap years. Best for age, anniversaries and contract terms.
Elapsed time
"827 days" or "19,848 hours." A raw count of time that has passed. Best for interest, SLAs, countdowns and anything measured in a single unit. One month here can be 28–31 days.
Privacy note: everything happens locally in your browser. Your dates are never sent to a server.
Date difference examples
| From | To | Calendar difference | Elapsed |
|---|---|---|---|
| 2026-01-01 | 2026-03-01 | 0y 2m 0d | 59 days · 1,416 hours |
| 2024-01-01 | 2024-03-01 | 0y 2m 0d | 60 days (2024 is a leap year) |
| 2025-08-31 | 2025-09-30 | 0y 1m 0d | 30 days |
| 2026-05-10 09:30 | 2026-05-10 17:45 | same day | 8h 15m · 8.25 hours · 495 min |
| 2026-05-10 22:00 | 2026-05-11 06:00 | 1 day (dates) | 8h 0m — overnight span |
Leap years matter: any range that crosses Feb 29 gains a day. Month boundaries matter too — Jan 31 → Feb 28 is counted as one calendar month even though it is only 28 elapsed days.
Frequently Asked Questions
How do I calculate the number of hours between two dates?+
Enter both dates and, if you need to-the-hour precision, add a start time and an end time. The calculator multiplies the elapsed days by 24 and adds the leftover hours from the times you entered, then also shows the same span in total minutes and total seconds.
How do I calculate the hours between two times?+
Use the same start date for both fields, set the start time and end time, and read the Total hours and Total minutes results. For a shift that runs past midnight, put the next calendar day in the end date so the overnight hours are counted. For a dedicated same-day time tool, use the Time Duration Calculator.
How is the calendar difference between two dates calculated?+
The years, months and days breakdown is computed by comparing the two dates the way you would by hand, borrowing days and months correctly across different month lengths and leap years, not by dividing total days by 365.
What is the difference between calendar difference and elapsed time?+
Calendar difference answers "how many whole years, months and days apart are these dates". Elapsed time answers "how many total days, hours, minutes or seconds have passed". One month can be 28, 29, 30 or 31 elapsed days, so the two views do not convert to each other with a fixed formula.
What does "include end date" change?+
It adds one extra day to the total-days, weekday and weekend counts, useful for questions like "how many days is my trip" where both the start and end day count as full days. It does not change the years/months/days breakdown or the hour/minute/second totals.
What happens if I enter the end date before the start date?+
The calculator still works. It shows the absolute difference between the two dates and notes which one comes first, rather than showing an error or a negative result. Use Swap to put them in order.
Does this avoid timezone bugs when calculating dates?+
Yes. Dates are parsed as calendar year/month/day values and compared using UTC-based day arithmetic, specifically to avoid the common bug where date-only calculations shift by a day depending on the browser's local timezone.
Does this tool store the dates I enter?+
No. All calculations happen locally in your browser. Nothing you enter is sent to a server or saved.