diff --git a/lib/index.js b/lib/index.js
index 571ccda..9b7bf4a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -520,6 +520,8 @@ GitStats.prototype.ansiCalendar = function (options, callback) {
  * @param {String|Object} options The repo path or an object containing the following fields:
  *
  *  - `repo` (String): The repository path.
+ *  - `start` (String): The start date.
+ *  - `end` (String): The end date.
  *
  * @param {Function} callback The callback function.
  * @return {GitStats} The `GitStats` instance.