diff --git a/README.md b/README.md
index 2c486301..1a5c0c6b 100755
--- a/README.md
+++ b/README.md
@@ -177,6 +177,17 @@ $('.datepicker').eq(0).pikaday('show').pikaday('gotoYear', 2042);
 </script>
 ```
 
+### Formatting
+
+If the `reposition` configuration-option is enabled (default), Pikaday will apply CSS-classes to the datepicker according to how it is positioned:
+
+* `top-aligned`
+* `left-aligned`
+* `right-aligned`
+* `bottom-aligned`
+
+Note that the DOM element at any time will typically have 2 CSS-classes (eg. `top-aligned right-aligned` etc).
+
 ## AMD support
 
 If you use a modular script loader than Pikaday is not bound to the global object and will fit nicely in your build process. You can require Pikaday just like any other module.
diff --git a/pikaday.js b/pikaday.js
index ba7aca06..45ec89de 100755
--- a/pikaday.js
+++ b/pikaday.js
@@ -1032,7 +1032,7 @@
 
         adjustPosition: function()
         {
-            var field, pEl, width, height, viewportWidth, viewportHeight, scrollTop, left, top, clientRect;
+            var field, pEl, width, height, viewportWidth, viewportHeight, scrollTop, left, top, clientRect, leftAligned, bottomAligned;
 
             if (this._o.container) return;
 
@@ -1045,6 +1045,8 @@
             viewportWidth = window.innerWidth || document.documentElement.clientWidth;
             viewportHeight = window.innerHeight || document.documentElement.clientHeight;
             scrollTop = window.pageYOffset || document.body.scrollTop || document.documentElement.scrollTop;
+            leftAligned = true;
+            bottomAligned = true;
 
             if (typeof field.getBoundingClientRect === 'function') {
                 clientRect = field.getBoundingClientRect();
@@ -1067,6 +1069,7 @@
                 )
             ) {
                 left = left - width + field.offsetWidth;
+                leftAligned = false;
             }
             if ((this._o.reposition && top + height > viewportHeight + scrollTop) ||
                 (
@@ -1075,10 +1078,16 @@
                 )
             ) {
                 top = top - height - field.offsetHeight;
+                bottomAligned = false;
             }
 
             this.el.style.left = left + 'px';
             this.el.style.top = top + 'px';
+
+            addClass(this.el, leftAligned ? 'left-aligned' : 'right-aligned');
+            addClass(this.el, bottomAligned ? 'bottom-aligned' : 'top-aligned');
+            removeClass(this.el, !leftAligned ? 'left-aligned' : 'right-aligned');
+            removeClass(this.el, !bottomAligned ? 'bottom-aligned' : 'top-aligned');
         },
 
         /**