Calculate Duration Between Two Dates With Time
Days between dates with a plethora of options
Use the time duration calculator to calcualte the number of days between two dates. You can check the box to exclude holidays and weekends if you like. We've included holidays from the United Kingdom, United States and Australia, do remember to pick a country if you select the holiday option.
Our Time Duration Calculator can help you determine the number of days between dates. Just enter your information below.
How to Use Our Calculator to Find Days Between Dates
- Enter your start date. Enter your start date on the left side of the calculator. You can either enter the date manually, or click the red calendar button to enter the date using a calendar interface.
- If desired, enter your start time. If you would like to be extra precise with your calculation, you can enter your start time into the time boxes. Or, if you don’t have a set start time, leave these boxes blank.
- Enter your end date. Enter your end date manually, or by using the calendar button.
- If desired, enter your end time. Enter the end time into the right half of the calculator.
- Decide if you’d like to exclude weekends and holidays. If you’d like to calculate only the business days that have passed between dates, you can choose to exclude weekends and holidays from your calculation by checking the appropriate box.
- Decide if you’d like to include the end date in your calculation. Including the end date in your calculation will add one day to the calculation.
- Click the red ‘calculate’ button. Once you’ve entered your parameters, click the red ‘calculate’ button and your results will be generated below. Our results include the days between dates, as well as the time between dates in different forms, including years, weeks, hours, minutes, and seconds.
When Was the First Calendar Invented?
Calendars have been around for thousands of years, and have existed in many forms. Different rulers and different countries have imposed different types of calendars on their citizens, sometimes for cultural or religious regions. For instance, the French Republican Calendar, which was first used in 1793, had three-week months and ten-day weeks, and was created to remove religious and royal references in the calendar. However, most calendars are quite similar to our current timekeeping system, including the first known calendar. Created by the Sumerians in Mesopotamia over 5,000 years ago, this calendar divided the year into 12 months, each of which contained 29 or 30 days.
Still, this calendar was plenty different from ours. The Sumerian calendar marked 360 days in a year, and each day had only 12 hours: 6 daytime and 6 nighttime hours. (Of course, an ‘hour’ then was much longer than it is today.) Interestingly, there were also no weeks or weekends. Instead of having leap years, there was a leap month every four years, which helped to offset the 5-day discrepancy from the year length on a modern calendar.
When Did the Modern Calendar Evolve?
The calendar currently used in most countries is the Gregorian calendar, which was created by Pope Gregory XIII in 1582. Pope Gregory XIII created the calendar, which replaced the Julian calendar from Rome, to ensure that everyone in Europe celebrated Easter on the appropriate day. This new calendar perfected the length of a year. Previously, the Julian calendar had slightly overestimated the number of days in a year. And by slight, we mean very slight: the Julian calendar overestimated the year’s length by 0.0075 days a year, meaning that every 128 years, an extra day was accidentally added to the calendar. Still, over the centuries, those days added up, causing the seasonal equinoxes to drift from their marked dates.
Even the Gregorian calendar isn’t perfectly accurate. It overestimates the number of days in the year by approximately 1 day every 7,700 years, meaning that, unless we add additional leap days every few thousand years, our calendar will slowly also begin to drift. In about 1,386,000 years, you can expect to celebrate Christmas in the sunny warmth of what we now call ‘July.’
Feedback on our Days Between Dates Calculator
What do you think about our Time Duration Calculator? Did this tool help you figure out the days between dates? Are there other features you’d like to see added? We’d love to hear from you! Click the ‘feedback’ button to share your suggestions.
If you're interested in other calculator tools, try our Time Calculator, which can help you determine the hours between times. We also have a Business Days Calculator, to help you determine the business days between dates.