diff --git a/snippets/isSameDate.md b/snippets/isSameDate.md
index 07041b84f..5e30edf4d 100644
--- a/snippets/isSameDate.md
+++ b/snippets/isSameDate.md
@@ -2,10 +2,10 @@
 
 Check if a date is the same as another date.
 
-Use strict equality checking (`===`) to check if the first date is the same as the second one.
+Use `Date.prototype.toISOString()` and strict equality checking (`===`) to check if the first date is the same as the second one.
 
 ```js
-const isSameDate = (dateA, dateB) => dateA === dateB;
+const isSameDate = (dateA, dateB) => dateA.toISOString() === dateB.toISOString();
 ```
 
 ```js
diff --git a/test/dayOfYear/dayOfYear.js b/test/dayOfYear/dayOfYear.js
new file mode 100644
index 000000000..8c6042edf
--- /dev/null
+++ b/test/dayOfYear/dayOfYear.js
@@ -0,0 +1,3 @@
+const dayOfYear = date =>
+  Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
+module.exports = dayOfYear;
diff --git a/test/dayOfYear/dayOfYear.test.js b/test/dayOfYear/dayOfYear.test.js
new file mode 100644
index 000000000..2df870a58
--- /dev/null
+++ b/test/dayOfYear/dayOfYear.test.js
@@ -0,0 +1,6 @@
+const expect = require('expect');
+const dayOfYear = require('./dayOfYear.js');
+
+test('dayOfYear is a Function', () => {
+  expect(dayOfYear).toBeInstanceOf(Function);
+});
diff --git a/test/degreesToRads/degreesToRads.js b/test/degreesToRads/degreesToRads.js
index ffc04f7fd..786f112e3 100644
--- a/test/degreesToRads/degreesToRads.js
+++ b/test/degreesToRads/degreesToRads.js
@@ -1,2 +1,2 @@
-const degreesToRads = deg => (deg * Math.PI) / 180.0;
+const degreesToRads = deg => deg * Math.PI / 180.0;
 module.exports = degreesToRads;
diff --git a/test/getMeridiemSuffixOfInteger/getMeridiemSuffixOfInteger.js b/test/getMeridiemSuffixOfInteger/getMeridiemSuffixOfInteger.js
index 6e91ea80c..8728f3637 100644
--- a/test/getMeridiemSuffixOfInteger/getMeridiemSuffixOfInteger.js
+++ b/test/getMeridiemSuffixOfInteger/getMeridiemSuffixOfInteger.js
@@ -4,6 +4,6 @@ const getMeridiemSuffixOfInteger = num =>
     : num === 12
       ? 12 + 'pm'
       : num < 12
-        ? (num % 12) + 'am'
-        : (num % 12) + 'pm';
+        ? num % 12 + 'am'
+        : num % 12 + 'pm';
 module.exports = getMeridiemSuffixOfInteger;
diff --git a/test/hz/hz.js b/test/hz/hz.js
index 7172074bb..c7d0b997b 100644
--- a/test/hz/hz.js
+++ b/test/hz/hz.js
@@ -1,6 +1,6 @@
 const hz = (fn, iterations = 100) => {
   const before = performance.now();
   for (let i = 0; i < iterations; i++) fn();
-  return (1000 * iterations) / (performance.now() - before);
+  return 1000 * iterations / (performance.now() - before);
 };
 module.exports = hz;
diff --git a/test/isAfterDate/isAfterDate.js b/test/isAfterDate/isAfterDate.js
new file mode 100644
index 000000000..e489c8439
--- /dev/null
+++ b/test/isAfterDate/isAfterDate.js
@@ -0,0 +1,2 @@
+const isAfterDate = (dateA, dateB) => dateA > dateB;
+module.exports = isAfterDate;
diff --git a/test/isAfterDate/isAfterDate.test.js b/test/isAfterDate/isAfterDate.test.js
new file mode 100644
index 000000000..4332eab5a
--- /dev/null
+++ b/test/isAfterDate/isAfterDate.test.js
@@ -0,0 +1,12 @@
+const expect = require('expect');
+const isAfterDate = require('./isAfterDate.js');
+
+test('isAfterDate is a Function', () => {
+  expect(isAfterDate).toBeInstanceOf(Function);
+});
+test('isAfterDate produces the correct result', () => {
+  expect(isAfterDate(new Date(2010, 10, 21), new Date(2010, 10, 20))).toBeTruthy();
+});
+test('isBeforeDate produces the correct result', () => {
+  expect(isAfterDate(new Date(2010, 10, 20), new Date(2010, 10, 21))).toBeFalsy();
+});
diff --git a/test/isBeforeDate/isBeforeDate.js b/test/isBeforeDate/isBeforeDate.js
new file mode 100644
index 000000000..cd6207544
--- /dev/null
+++ b/test/isBeforeDate/isBeforeDate.js
@@ -0,0 +1,2 @@
+const isBeforeDate = (dateA, dateB) => dateA < dateB;
+module.exports = isBeforeDate;
diff --git a/test/isBeforeDate/isBeforeDate.test.js b/test/isBeforeDate/isBeforeDate.test.js
new file mode 100644
index 000000000..5656970c1
--- /dev/null
+++ b/test/isBeforeDate/isBeforeDate.test.js
@@ -0,0 +1,13 @@
+const expect = require('expect');
+const isBeforeDate = require('./isBeforeDate.js');
+
+test('isBeforeDate is a Function', () => {
+  expect(isBeforeDate).toBeInstanceOf(Function);
+});
+test('isBeforeDate produces the correct result', () => {
+  expect(isBeforeDate(new Date(2010, 10, 20), new Date(2010, 10, 21))).toBeTruthy();
+});
+test('isBeforeDate produces the correct result', () => {
+  expect(isBeforeDate(new Date(2010, 10, 21), new Date(2010, 10, 20))).toBeFalsy();
+});
+
diff --git a/test/isSameDate/isSameDate.js b/test/isSameDate/isSameDate.js
new file mode 100644
index 000000000..3bd6f2218
--- /dev/null
+++ b/test/isSameDate/isSameDate.js
@@ -0,0 +1,2 @@
+const isSameDate = (dateA, dateB) => dateA.toISOString() === dateB.toISOString();
+module.exports = isSameDate;
diff --git a/test/isSameDate/isSameDate.test.js b/test/isSameDate/isSameDate.test.js
new file mode 100644
index 000000000..2b6e8cbd4
--- /dev/null
+++ b/test/isSameDate/isSameDate.test.js
@@ -0,0 +1,12 @@
+const expect = require('expect');
+const isSameDate = require('./isSameDate.js');
+
+test('isSameDate is a Function', () => {
+  expect(isSameDate).toBeInstanceOf(Function);
+});
+test('isSameDate produces the correct result', () => {
+  expect(isSameDate(new Date(2010, 10, 20), new Date(2010, 10, 20))).toBeTruthy();
+});
+test('isSameDate produces the correct result', () => {
+  expect(isSameDate(new Date(2010, 10, 20), new Date(2010, 10, 21))).toBeFalsy();
+});
diff --git a/test/lcm/lcm.js b/test/lcm/lcm.js
index a4d8b1032..60ef96de8 100644
--- a/test/lcm/lcm.js
+++ b/test/lcm/lcm.js
@@ -1,6 +1,6 @@
 const lcm = (...arr) => {
   const gcd = (x, y) => (!y ? x : gcd(y, x % y));
-  const _lcm = (x, y) => (x * y) / gcd(x, y);
+  const _lcm = (x, y) => x * y / gcd(x, y);
   return [...arr].reduce((a, b) => _lcm(a, b));
 };
 module.exports = lcm;
diff --git a/test/luhnCheck/luhnCheck.js b/test/luhnCheck/luhnCheck.js
index d666a021a..20a62dd17 100644
--- a/test/luhnCheck/luhnCheck.js
+++ b/test/luhnCheck/luhnCheck.js
@@ -4,7 +4,7 @@ const luhnCheck = num => {
     .reverse()
     .map(x => parseInt(x));
   let lastDigit = arr.splice(0, 1)[0];
-  let sum = arr.reduce((acc, val, i) => (i % 2 !== 0 ? acc + val : acc + ((val * 2) % 9) || 9), 0);
+  let sum = arr.reduce((acc, val, i) => (i % 2 !== 0 ? acc + val : acc + (val * 2) % 9 || 9), 0);
   sum += lastDigit;
   return sum % 10 === 0;
 };
diff --git a/test/maxDate/maxDate.js b/test/maxDate/maxDate.js
new file mode 100644
index 000000000..b2413c849
--- /dev/null
+++ b/test/maxDate/maxDate.js
@@ -0,0 +1,2 @@
+const maxDate = (...dates) => new Date(Math.max.apply(null, ...dates));
+module.exports = maxDate;
diff --git a/test/maxDate/maxDate.test.js b/test/maxDate/maxDate.test.js
new file mode 100644
index 000000000..e7d6ae60c
--- /dev/null
+++ b/test/maxDate/maxDate.test.js
@@ -0,0 +1,15 @@
+const expect = require('expect');
+const maxDate = require('./maxDate.js');
+
+test('maxDate is a Function', () => {
+  expect(maxDate).toBeInstanceOf(Function);
+});
+test('maxDate produces the maximum date', () => {
+  const array = [
+    new Date(2017, 4, 13),
+    new Date(2018, 2, 12),
+    new Date(2016, 0, 10),
+    new Date(2016, 0, 9)
+  ];
+  expect(maxDate(array)).toEqual(new Date(2018, 2, 12));
+});
diff --git a/test/minDate/minDate.js b/test/minDate/minDate.js
new file mode 100644
index 000000000..a740098ed
--- /dev/null
+++ b/test/minDate/minDate.js
@@ -0,0 +1,2 @@
+const minDate = (...dates) => new Date(Math.min.apply(null, ...dates));
+module.exports = minDate;
diff --git a/test/minDate/minDate.test.js b/test/minDate/minDate.test.js
new file mode 100644
index 000000000..7156eb98b
--- /dev/null
+++ b/test/minDate/minDate.test.js
@@ -0,0 +1,15 @@
+const expect = require('expect');
+const minDate = require('./minDate.js');
+
+test('minDate is a Function', () => {
+  expect(minDate).toBeInstanceOf(Function);
+});
+test('minDate produces the maximum date', () => {
+  const array = [
+    new Date(2017, 4, 13),
+    new Date(2018, 2, 12),
+    new Date(2016, 0, 10),
+    new Date(2016, 0, 9)
+  ];
+  expect(minDate(array)).toEqual(new Date(2016, 0, 9));
+});
diff --git a/test/percentile/percentile.js b/test/percentile/percentile.js
index 07669d78b..fd32602d2 100644
--- a/test/percentile/percentile.js
+++ b/test/percentile/percentile.js
@@ -1,3 +1,3 @@
 const percentile = (arr, val) =>
-  (100 * arr.reduce((acc, v) => acc + (v < val ? 1 : 0) + (v === val ? 0.5 : 0), 0)) / arr.length;
+  100 * arr.reduce((acc, v) => acc + (v < val ? 1 : 0) + (v === val ? 0.5 : 0), 0) / arr.length;
 module.exports = percentile;
diff --git a/test/radsToDegrees/radsToDegrees.js b/test/radsToDegrees/radsToDegrees.js
index fde727a2f..214e5defa 100644
--- a/test/radsToDegrees/radsToDegrees.js
+++ b/test/radsToDegrees/radsToDegrees.js
@@ -1,2 +1,2 @@
-const radsToDegrees = rad => (rad * 180.0) / Math.PI;
+const radsToDegrees = rad => rad * 180.0 / Math.PI;
 module.exports = radsToDegrees;