What is CentWatch?
CentWatch is an iPhone app used in Time-Speed-Distance (TSD) rally competition to view time in hundredths of a minute (sometimes referred to as "cents"). It can display the current "wall" time and elapsed stopwatch time in cents.
Why would you want to do that?
In TSD rally, competitors need to determine the correct time (within a second) that they should be passing each point along the timed second. One method to do this involves calculations and these calculations produce values with fractional minutes (tenths, hundredths or more precise, depending on the values uses in the calculations). Using a clock that displays time in fractional minutes saves the competitor from having to convert the calculated time value to seconds.
Why can't you just use a regular clock or stopwatch?
You could, but, as noted above, an extra conversion needs to be done.
What devices does ATC Calculator run on?
iPhone, iPod touch and iPad. A predecessor app called TSDWatch runs on Palm.
How do you use it?
The app displays the current time as well as a stopwatch. Use it like you would use a normal clock or stopwatch.
You can adjust the clock time to match the event time using the 'Adj' button. You can change the color of the display as appropriate for the lighting conditions with a switch. You can display time in standard hour:minute:second format through a switch as well.
How would I use this during a TSD rally?
This depends on the timing method that you use when you compete. Choosing the best timing method to use is beyond the scope of this FAQ.