TimeCalc is a desktop calculator with a difference. As well as working with the decimal numbers we are all used to working with, TimeCalc will also work with sexagesimal numbers. Numbers that are in base-60 such as times. This is useful when you want to perform calculations on time expressed in hours minutes and seconds. We think of a time such as 2:28:24 as 2 hours, 28 minutes and 24 seconds, but to perform calculations on this using other calculators you would first have to convert it to 2.4733 hours or 148.4 minutes or 8904 seconds. When we get the result, say dividing by three, we then have to convert this decimal value back into a time we can understand. TimeCalc does all this for you. Not only can it easy handle the conversion from decimal to time values, but it will also allow you to enter the time values directly in the notation you are familiar with and give you the result in the same format.
For example you can enter 2:28:24 ÷ 3 into TimeCalc and it will give you the answer 49:28
There are two ways to enter time values
The first is to use the : You do this much as you would would use the. to enter fractional decimal values. You can use either one or two : to enter a value in hours, minutes and seconds or just minutes and seconds. You may also use the . to enter a fractional number of seconds.
For example 1:30:00 for one hour thirty or 2:20.5 for two minutes twenty point five.
The second way is to use the hour, min and sec buttons. These buttons convert between decimal and time notation. So if you press 3 then hour you get 3:00:00. Which is a convenient shortcut.
Note: When you are entering time values using the : button you may find that the calculator becomes unresponsive to certain numbers or operations. This is because the number is in an incomplete state and cannot be used until you have entered both digits after the : The first digit after the : must be in the range 0-5, so pressing numbers 6-9 at this point will do nothing.
The hour min sec buttons are used to convert between decimal and time notation. When converting from a decimal value to a time value you need to specify whether the value represents hours, mins or seconds. So 2.5 hour -> 2:30:00 but 2.5 min -> 2:30 and 2.5 sec -> 0:02.5
Equally when we are converting back the other way we also need to specify whether we want the number of hours, mins or seconds. So 2:30:00 hour goes back to 2.5 but 2:30:00 min gives 150 and 2:30:00 sec gives 9000
We can use a combination of these buttons to convert from hours to minutes or seconds. For example to quickly see the number of seconds in a day you could use 24 hour sec -> 86400
TimeCalc may be used for any time-based calculations but it is specifically designed to help runners and running coaches. For this reason it comes with some useful preprogramed values
Mar - Marathon distance, Press once for the distance of a marathon in kilometres and twice for the distance in miles.
HM -Half Marathon distance, Press once for the distance of a half marathon in kilometres and twice for the distance in miles.
mile - Mile distance. Press once for the length of a mile in kilometers and twice for the length of a mile in metres. The first value is very useful for converting between miles and kilometers and mile and kilometre pace.
yard - The length of a yard in metres.
Another feature of the TimeCalc calculator is that it has a backwards division button \ This performs a normal division, but the other way round. So instead of returning the first number divided by the second it returns the second number divided by the first. We sometimes do the same in speech when expressing a division. We can say 12 divided by 3 is 4. Or we can say 3 into 12 goes 4 times. So think of this as the "into" or "in" button.
For example what pace am I going if I run a marthon in 3 hours? With TimeCalc this is easy!
Mar \ 3 hour = 4:15.95 min/km or
Mar Mar \ 3 hour = 6:51.92 min/mi
TimeCalc also makes it easy to create sequences.
Pressing = after a calculation will repeat the last operation on the result. So if you wanted to create a sequence of running distances starting at 8 miles and increasing by 10% you could press 8 x 1.1 = Which gives 8.8 Then pressing = again gives you the next value in the sequence 9.68. The pressing = a third time gives the third value in the sequence 10.648 and so on.
You can also create a sequence from the current value using + = in combination. Quite often you want to create a sequence using the value you have just calculated that increases by that amount each time. For example to calculate your mile splits. First do the calculation to get the time per mile, then press + =. Now each time you press = again it will give you your split time for the next mile.
For example to get the mile split times for a 3:15:00 hour marathon,
Mar Mar \ 3:15:00 = This is the result of the calculation 7:26.24
+= Starts sequence using this value. This is the first in the sequence. Same as result before. 7:26.24
= Returns the second value in the sequence 14:52.48
= Returns the next value in the sequence 22:18.72
etc.
Working with a combination of decimal and time vales does give more scope for things to go wrong. You may find yourself looking at a result that just says Error! If this happens, you will need to reset using the AC (all clear) button to continue.
These are the operations that could cause an error
Division by zero - same as any other calculator
Adding or subtracting a time value and a decimal. You can't for example add 2 to 2:20 because what does that mean? Add 2 seconds? Add 2 minutes or add 2 hours? If you want to add 2 seconds you convert the 2 to a time value using the sec button and then the addition will work fine.
Dividing a decimal value by a time value. Again because it makes no sense. The other way round is fine. (As is dividing one time value with another.) So if you enter the decimal value first you probably want to use the reverse division or "into" operator \
Multiplying two time values together.
If you make a mistake while entering a value, you can either remove the last digit entered using <Del or the whole value using C. Pressing AC resets the calculator clearing the current value and cancels any operation in progress. It is also the only way to clear an Error! state. AC will not clear the value stored in memory with MS or M+. To clear the memory use MC.
TimeCalc follows basic precedence rules. Namely, multiplications and divisions are performed before additions and subtractions. So
1 + 2 x 3 = -> 7 (not 9)
You can force left-to-right calculation by pressing = after each operation. So
1 + 2 = x 3 = -> 9
This also has an implication for when the = button is used to repeat the last operation. In the first example above the last operation is to add 6 (because the 2 x 3 is done before). So pressing = again will add six again, yielding 13. In the second example the last operation was to multiply by 3. So pressing = again will multiply by 3 again, yielding 27.
This has changed. Prior to version 1.1.0, \ (into) had the same precedence as multiply and divide. (The rationale for this was that it was most similar to these operations.) From version 1.1.0 the precedence of \ is the same as addition and subtraction. This is the result of more research and this article in particular: http://jkorpela.fi/latin1/confra.html . But it also allows for much more powerful conversions.
For example
7 \ 1 hour ÷ mile = -> 5:19.56
To convert 7 mph into min/km pace. But now because the last operation was to backwards divide into 1:00:00 / 1.609344, pressing = will repeat this operation on whatever the current value is allowing us to repeat the conversion to and from mph and min/km with a single key press.
8 = -> 4:39.62
4:00 = -> 9.32...
Decimal values are displayed with the maximum number of decimal places that the display width will allow. However, time values are only displayed to the nearest hundredth of a second even if the exact value has more decimal places than this. This is because for the type of time-based calculations TimeCalc was designed for, more accuracy than this is not required and adding more decimal places would just clutter the display. If you wish to see the full fractional value of a time, just press the sec button to convert to the decimal value of the number of seconds.
2 sec ÷ 3 = -> 0:00.67
sec -> 0.6666666667
You don't have to bookmark this site. When TimeCalc first starts it displays a hyperlink to this site along with the version number. Clicking on the link will bring you back to this site where you can find this documentation, check if there is an updated version, or leave some feedback.
Although this information disappears as soon as you start using the calculator, you can get it back at anytime by pressing the AC button twice.