1 files changed, 39 insertions, 0 deletions
diff --git a/date-fns/src/differenceInMilliseconds/index.ts b/date-fns/src/differenceInMilliseconds/index.ts
new file mode 100644
index 0000000..a0fc552
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/index.ts
@@ -0,0 +1,39 @@
+import toDate from '../toDate/index'
+import requiredArgs from '../_lib/requiredArgs/index'
+
+/**
+ * @name differenceInMilliseconds
+ * @category Millisecond Helpers
+ * @summary Get the number of milliseconds between the given dates.
+ *
+ * @description
+ * Get the number of milliseconds between the given dates.
+ *
+ * ### v2.0.0 breaking changes:
+ *
+ * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
+ *
+ * @param {Date|Number} dateLeft - the later date
+ * @param {Date|Number} dateRight - the earlier date
+ * @returns {Number} the number of milliseconds
+ * @throws {TypeError} 2 arguments required
+ *
+ * @example
+ * // How many milliseconds are between
+ * // 2 July 2014 12:30:20.600 and 2 July 2014 12:30:21.700?
+ * const result = differenceInMilliseconds(
+ *   new Date(2014, 6, 2, 12, 30, 21, 700),
+ *   new Date(2014, 6, 2, 12, 30, 20, 600)
+ * )
+ * //=> 1100
+ */
+export default function differenceInMilliseconds(
+  dirtyDateLeft: Date | number,
+  dirtyDateRight: Date | number
+): number {
+  requiredArgs(2, arguments)
+
+  const dateLeft = toDate(dirtyDateLeft)
+  const dateRight = toDate(dirtyDateRight)
+  return dateLeft.getTime() - dateRight.getTime()
+}