# Leap Given a year, report if it is a leap year. The tricky thing here is that a leap year in the Gregorian calendar occurs: ```text on every year that is evenly divisible by 4 except every year that is evenly divisible by 100 unless the year is also evenly divisible by 400 ``` For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap year, but 2000 is. ## Notes Though our exercise adopts some very simple rules, there is more to learn! For a delightful, four minute explanation of the whole leap year phenomenon, go watch [this youtube video][video]. [video]: http://www.youtube.com/watch?v=xX96xng7sAE You will see a `cases_test.go` file in this exercise. This holds the test cases used in the `leap_test.go`. You can mostly ignore this file. However, if you are interested... we sometimes generate the test data from a [cross language repository][problem-specifications-leap]. In that repo exercises may have a [.json file][problem-specifications-leap-json] that contains common test data. Some of our local exercises have an [intermediary program][local-leap-gen] that takes the problem specification JSON and turns in into Go structs that are fed into the `_test.go` file. The Go specific transformation of that data lives in the `cases_test.go` file. [problem-specifications-leap]: https://github.com/exercism/problem-specifications/tree/master/exercises/leap [problem-specifications-leap-json]: https://github.com/exercism/problem-specifications/blob/master/exercises/leap/canonical-data.json [local-leap-gen]: https://github.com/exercism/go/blob/master/exercises/leap/.meta/gen.go ## Coding the solution Look for a stub file having the name leap.go and place your solution code in that file. ## Running the tests To run the tests run the command `go test` from within the exercise directory. If the test suite contains benchmarks, you can run these with the `--bench` and `--benchmem` flags: go test -v --bench . --benchmem Keep in mind that each reviewer will run benchmarks on a different machine, with different specs, so the results from these benchmark tests may vary. ## Further information For more detailed information about the Go track, including how to get help if you're having trouble, please visit the exercism.io [Go language page](http://exercism.io/languages/go/resources). ## Source JavaRanch Cattle Drive, exercise 3 [http://www.javaranch.com/leap.jsp](http://www.javaranch.com/leap.jsp) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.