diff --git a/js/datepicker.js b/js/datepicker.js
index aa03601..e89558d 100644
--- a/js/datepicker.js
+++ b/js/datepicker.js
@@ -192,7 +192,11 @@
          * can also be 'click' for instance if the trigger element is a button
          * or some text element. 
          */
-        showOn: 'focus',
+        showOn: 'focus',
+        /**
+        * Whether or not to allow dates in the past to be selectable, boolean, defaults to true
+        */
+        pastDatesSelectable: true,
         /**
          * Callback, invoked prior to the rendering of each date cell, which 
          * allows control of the styling of the cell via the returned hash.
@@ -346,6 +350,10 @@
             if (date > today) {
               // current month, date in future
               data.weeks[indic].days[indic2].classname.push('datepickerFuture');
+            }
+
+            if (date < today && !options.pastDatesSelectable) {
+              data.weeks[indic].days[indic2].classname.push('datepickerDisabled');
             }
             
             if (month != date.getMonth()) {