Calculate the moment when someone has lived for 10^9 seconds.
A gigasecond is 10^9 (1,000,000,000) seconds.
You can run all the tests for an exercise by entering
$ gradle testin your terminal.
Chapter 9 in Chris Pine's online Learn to Program tutorial. http://pine.fm/LearnToProgram/?Chapter=09
It's possible to submit an incomplete solution so you can see how others have completed the exercise.