TimeCalc is a very simple utility for calculating times. I use it for calculating splits or predicting race times. It is a calculator that supports doubles and times. For example:
If I run 5 kilometers at 3:30/kilometer, the race will take me 17:30.
If I want to know how fast my splits need to be in order to run a 10K in 37:00.
If I want to add two times:
Or calculating the splits Bekele needs to run on the marathon:
Which is very fast, indeed.