sample test added:
describe("cellStates", function() {
it("Test, Initial state is [1, 1, 1, 1, 0, 1, 1, 1] period of time is 1 day", function() {
Test.assertSimilar(cellStates([1, 1, 1, 1, 0, 1, 1, 1],1), [ 1, 0, 0, 1, 0, 1, 0, 1 ], "Expected result after 1 day is [ 1, 0, 0, 1, 0, 1, 0, 1 ]");
});
});

initial code added:
function cellStates(states, days) {

}

Tests added.

hit published too soon. Tests added.