Hours Between Dates Calculator — Find the Exact Hours Between Any Two Dates
Use this free hours between dates calculator to find the exact number of hours between any two dates and times. Enter your start and end datetime for an instant result showing total hours, hours and minutes, total days and total minutes.
How to Calculate Hours Between Two Dates
To find the number of hours between two dates, subtract the start date from the end date to get the total difference in milliseconds, then divide by 3,600,000 (the number of milliseconds in an hour).
The calculator also accepts specific times — so you can calculate the hours between 9am on Monday and 5pm on Friday, for example.
Hours in Common Time Periods
Here are the most frequently needed hour conversions for quick reference:
| Time Period | Total Hours | Total Minutes |
|---|---|---|
| 1 day | 24 hours | 1,440 minutes |
| 1 week | 168 hours | 10,080 minutes |
| 1 month (avg) | 730 hours | 43,800 minutes |
| 1 year | 8,760 hours | 525,600 minutes |
| Working week (9-5) | 40 hours | 2,400 minutes |
| Working month | 173 hours | 10,380 minutes |
When Would You Need Hours Between Dates?
Hours Between Dates vs Days Between Dates
- Days between dates gives you a whole number — useful for general planning
- Hours between dates is more precise — essential when specific times matter
- For shift work and billing, hours are usually the required unit
- The calculator works for both — if you leave the time fields at 00:00 it calculates whole days multiplied by 24
FAQs
How do I calculate hours between two dates?
Select your start date and end date using the date pickers, then click Calculate Hours. You can also add specific times for a more precise result.
How many hours are in a week?
There are 168 hours in a week — 7 days multiplied by 24 hours.
How many hours are in a year?
There are 8,760 hours in a standard year and 8,784 hours in a leap year.
Can I calculate hours including specific times?
Yes — the calculator includes time fields so you can calculate the exact hours and minutes between any two date and time combinations.
Is this calculator free?
Yes — completely free, no sign-up required.