Fixed es5 syntax.

tangbc · tangbc · commit a09b52078cc9 · 2017-09-28T21:52:32.000+08:00
diff --git a/index.js b/index.js
@@ -244,7 +244,7 @@
             },
 
             // return the right zone info base on `start/index`.
-            getZone (index) {
+            getZone: function (index) {
                 var start, end
                 var delta = this.delta
 
