Time Duration Calculator


Start Time


End Time

Time Difference









How to use

This time duration calculator tool uses a date-time system.

Put in the date, and/or put in the time. Do this for start and end times. The tool will automatically calculate the duration between the two points in time.

Here’s a quick step-by-step walkthrough.

1. Start Time

Start with the calendar. Select the correct start date. You can use the arrows on the calendar to go back or forward one month.

Below the calendar you will see the following 3 fields:

hh mm ss

As you may have guessed, this is where you will input your time units.

hh = hour (time of day)

mm = minutes

ss = seconds

You can fill in the exact time of day. If you don’t need to calculate down to the minute or second, you can leave these fields blank.

2. End Time

Repeat the process you used to enter the start time.

Start with the calendar end date if you have one. Or fill in the time of day in hours, minutes, and seconds.

Time Difference

Once you plug in start time and end time, the time difference calculator instantly does its work.

It displays the time value between starting time and end time. In other words, the answer you’ve been looking for.

Time difference is calculated in days, hours, minutes, and seconds.

Notes on usage

Note that this date calculator uses 24-hour time. This time format prevents mistakes that can arise from the AM/PM clock time system.

For example, say you have a start time of 9:15 AM and an end time of 6:45 PM.

6:45 PM becomes 18:45. Enter “9 15 00” as the start time and “18 45 00” as the end time. The time difference is 9 hours and 30 minutes.

It’s just easier this way.

On that note, it’s also worth considering the time zone. Will you be in the same place when the end date-time hits?

For example, maybe your start time is in San Francisco on Pacific Standard Time. But 2 weeks later is your end time. At which point you’ll be in New York on Eastern Standard Time.

Best practice would be to defer to the time zone of your start time (PST). Simply convert the end time (EST) into PST. Just move it 3 hours back.

Consider also when you’re dealing with very different time zones. You may end up pushing the end date into the next day. Or moving it back to one day earlier.

Say you have to send a design brief to Hong Kong by 9 AM on Monday. You live in Seattle on PST (UTC -7 hours). Hong Kong is 15 hours ahead of you on HKT (UTC +8 hours).

Best to convert their time into yours. Your end time will be 6 PM Sunday night PST.

Time Duration Calculator

Planning, goal setting, meeting deadlines.

It’s not easy to estimate the amount of time it takes to do things. Or the amount of time between important events.

But it is of course very important.

Time management allows you to plan your work in a sustainable, effective way.

You can allocate resources intelligently and not end up having to break commitments. You can stop ideating and get things done.

Time management is necessary because time is fickle.

Sometimes we can do a lot in a short amount of time. Sometimes it seems we can’t get much done at all.

Procrastination often seeps in when we don’t have a definite deadline. Or when we have an inflated sense of how much time we have to accomplish goals.

It’s not good to feel under the gun. Having too short an amount of time to complete tasks can lead to spotty results. It can lead to burnout as well.

We all find our own strategies. Work management apps, spreadsheets, and calendars can help. But ultimately everyone develops their own pattern that works.

Still, everyone can agree on one thing. Step one is knowing exactly how much time you have.

A time duration calculator can help.

This freeware tool takes times and dates from a calendar. Then it turns them into tangible blocks of time.

You can calculate the time interval between A and B. Where A is start time and B is ending time. It’s as simple as that.

Know the time difference down to the smallest unit. Number of days, number of hours, minutes, and seconds.

Of course, you don’t need to use this tool just for looking between a current time and a future time. You can use it to find out the duration between two times of any kind.

You can even use this tool as an age calculator. If you know your exact time of birth, you can find out your age down to the minute.

Maybe you don’t want to go that far back. In that case, just use it to see how many days it’s been since your last birthday. Or to see how many days there are until your friend or spouse’s next birthday.

Use it to set a countdown timer too. Calculate the time difference, then get on your iPhone or Android device and set a timer. That way you can carry your ticking clock with you.

A time duration calculator is particularly useful during crunch times. Or sprints at work. 

You can use the time calculator to plan your extra-long productivity days. Seeing as you won’t be on a “normal” schedule, adjustment is important.

Avoid the possibility of undergrad style “all-nighters.” Set aside sufficient time for mental breaks and cooking dinner. Self-care and meditation.

This can keep you from feeling totally overwhelmed. You can manage your stress. And keep your personal life and well-being in better shape too.

As you can see, a date duration calculator has many applications. About as many as you can imagine really.

We hope you find it useful.