diff --git a/test/cycle-length.spec.js b/test/cycle-length.spec.js
index 043cf96d34a355993549b1c400e99bb509645d63..ee05fcb54e70b86f9fa339babc0a8e8c39be8861 100644
--- a/test/cycle-length.spec.js
+++ b/test/cycle-length.spec.js
@@ -17,7 +17,7 @@ describe('getCycleLengthStats', () => {
       stdDeviation: 53.06
     }
     expect(result).to.eql(expectedResult)
-  })
+  }),
 
   it('works for a simple even-numbered array', () => {
     const cycleLengths = [4, 1, 15, 2, 20, 5]
@@ -30,7 +30,8 @@ describe('getCycleLengthStats', () => {
       stdDeviation: 7.78
     }
     expect(result).to.eql(expectedResult)
-  })
+  }),
+
   it('works for an one-element array', () => {
     const cycleLengths = [42]
     const result = cycleInfo(cycleLengths)
@@ -42,20 +43,60 @@ describe('getCycleLengthStats', () => {
       stdDeviation: null
     }
     expect(result).to.eql(expectedResult)
+  }),
+
+  describe('works for more realistic examples', () => {
+    it('1 day difference between shortest and longest period', () => {
+      const cycleLengths = [28, 29, 28, 28, 28, 29, 28, 28, 28, 29, 29, 28]
+      const result = cycleInfo(cycleLengths)
+      const expectedResult = {
+        minimum: 28,
+        maximum: 29,
+        mean: 28.33,
+        median: 28,
+        stdDeviation: 0.49
+      }
+      expect(result).to.eql(expectedResult)
+    }),
+    it('3 days difference between shortest and longest period', () => {
+      const cycleLengths = [28, 29, 28, 28, 27, 30, 28, 27, 28, 28, 29, 27]
+      const result = cycleInfo(cycleLengths)
+      const expectedResult = {
+        minimum: 27,
+        maximum: 30,
+        mean: 28.08,
+        median: 28,
+        stdDeviation: 0.90
+      }
+      expect(result).to.eql(expectedResult)
+    }),
+    it('8 days difference between shortest and longest period', () => {
+      const cycleLengths = [28, 32, 29, 27, 28, 26, 33, 28, 29, 34, 27, 29]
+      const result = cycleInfo(cycleLengths)
+      const expectedResult = {
+        minimum: 26,
+        maximum: 34,
+        mean: 29.17,
+        median: 28.5,
+        stdDeviation: 2.52
+      }
+      expect(result).to.eql(expectedResult)
+    })
   })
+
   describe('when args are wrong', () => {
     it('throws when arg object is an empty array', () => {
       const cycleLengths = []
       expect(() => cycleInfo(cycleLengths).to.throw(AssertionError))
-    })
+    }),
     it('throws when arg object is not in right format', () => {
       const wrongObject = { hello: 'world' }
       expect(() => cycleInfo(wrongObject).to.throw(AssertionError))
-    })
+    }),
     it('throws when arg array contains a string', () => {
       const wrongElement = [4, 1, 15, '2', 20, 5]
       expect(() => cycleInfo(wrongElement).to.throw(AssertionError))
-    })
+    }),
     it('throws when arg array contains a NaN', () => {
       const wrongElement = [4, 1, 15, NaN, 20, 5]
       expect(() => cycleInfo(wrongElement).to.throw(AssertionError))