Add isCustomDate to apply custom CSS class to individual dates

daterangepicker.js

@@ -257,6 +257,9 @@
         if (typeof options.isInvalidDate === 'function')
             this.isInvalidDate = options.isInvalidDate;
 
+        if (typeof options.isCustomDate === 'function')
+            this.isCustomDate = options.isCustomDate;
+
         if (typeof options.alwaysShowCalendars === 'boolean')
             this.alwaysShowCalendars = options.alwaysShowCalendars;
 
@@ -509,6 +512,10 @@
             return false;
         },
 
+        isCustomDate: function() {
+            return false;
+        },
+
         updateView: function() {
             if (this.timePicker) {
                 this.renderTimePicker('left');
@@ -806,6 +813,15 @@
                     if (this.endDate != null && calendar[row][col] > this.startDate && calendar[row][col] < this.endDate)
                         classes.push('in-range');
 
+                    //apply custom classes for this date
+                    var isCustom = this.isCustomDate(calendar[row][col]);
+                    if (isCustom !== false) {
+                        if (typeof isCustom === 'string')
+                            classes.push(isCustom);
+                        else
+                            Array.prototype.push.apply(classes, isCustom);
+                    }
+
                     var cname = '', disabled = false;
                     for (var i = 0; i < classes.length; i++) {
                         cname += classes[i] + ' ';

website/index.html

@@ -655,6 +655,11 @@ <h2>Options</h2>
                                 calendars before they are displayed, and may return true or false to indicate whether
                                 that date should be available for selection or not.
                             </li>
+                            <li>
+                                <code>isCustomDate</code>: (function) A function that is passed each date in the two
+                                calendars before they are displayed, and may return a string or array of CSS class names
+                                to apply to that date's calendar cell.
+                            </li>
                             <li>
                                 <code>autoUpdateInput</code>: (boolean) Indicates whether the date range picker should
                                 automatically update the value of an <code>&lt;input&gt;</code> element it's attached to