Subtract Time Calculator
This subtract time calculator with its selfexplanatory name will (guess what) enable you to subtract time in various units conveniently.
If you're sometimes confused about time, don't worry  it's not just you, the concept of time still troubles even the greatest philosopher. Luckily, you have been given the infinite web resources to help you navigate the complex reality we live in. In the text below, you'll find instructions on how to subtract time using the subtract time calculator and how to add and subtract time on your own.
Whether you want to determine your working time, count only the Wednesdays within a given period, check what date it will be in 3 weeks, or are changing the time zones  we've got all types of time math calculators to clear some of the confusion surrounding time!
How to subtract time with this time math calculator

Choose adequate units in all fields of the subtract time calculator. By default, they are set to hours, minutes, and seconds, so that you can input any or all of these three units. You can also go for milliseconds, days, weeks, months, million years, billion years, or even the age of the universe (13.8 billion years)!

Input the value from which you want to subtract ("Time 1") into the time math calculator.

Input the value which you wish to subtract ("Time 2").

Check out the result in the last field ("Time difference") of the subtract time calculator. You can always change the unit it is displayed in.
How to add and subtract time by yourself
Adding and subtracting time on your own can be confusing. It's probably because we're used to using the decimal system:
1 m = 10 dm
,
while seconds and hours obey the sexagesimal system:
1 h = 60 min
and
1 min = 60 s
.
Let's go through some examples of how to add and subtract time when you don't have access to time math calculators.
How to subtract time:

Convert Time 1 and Time 2 to simpler units if you need to. For example, if you have to subtract 1 h 20 min 30 s from 2 h 14 min 16 s, you may first convert them to seconds:
Time 1:
t1 = 2 h 14 min 16 s
t1 = 2 * 60 * 60 s + 14 * 60 s + 16 s
t1 = 8056 s
Time 2:
t2 = 1 h 20 min 30 s
t2 = 1 * 60 * 60 s + 20 * 60 s + 30 s
t2 = 4830 s

Subtract the converted times:
t1  t2 = 8056 s  4830 s
t1  t2 = 3226 s

Convert the result to the target unit by dividing it by 60 (the remainder becomes the seconds):
3226 / 60 = 53 R 46
t1  t2 = 53 min 46 s
How to add time:
You can add time analogously. Another method is to add hours to hours, minutes to minutes, seconds to seconds (weeks to weeks, etc.) Let's say you want to add 3 h 54 min 46 s to 19 h 33 min 55 s:

Add hours:
3 h + 19 h = 22 h

Add minutes:
54 min + 33 min = 87 min
Convert the result to hours  divide minutes by 60 and leave the remainder as minutes:
87 min / 60 = 60 / 60 min + 27 / 60 min
87 min = 1 h 27 min

Add seconds:
46 s + 55 s = 101 s
101 s = 60 s + 41 s
101 s = 1 min 41s

Add the results from steps 13:
22 h + 1 h 27 min + 1 min 41s = 23 h 28 min 41 s