diff --git a/css/style.css b/css/style.css
index 0756dfe..985f864 100644
--- a/css/style.css
+++ b/css/style.css
@@ -155,7 +155,7 @@
     text-align: center;
 }
 
-.fn-gantt .rightPanel .month, .fn-gantt .rightPanel .year {
+.fn-gantt .rightPanel .weekyear, .fn-gantt .rightPanel .month, .fn-gantt .rightPanel .year {
     float: left;
     overflow: hidden;
     border-left: 1px solid #DDD;
diff --git a/index.html b/index.html
index dd193db..9af9e61 100644
--- a/index.html
+++ b/index.html
@@ -221,6 +221,17 @@ <h2 id="config">
                             string
                         </td>
                     </tr>
+                    <tr>
+                        <td>
+                            <code>weekYearPrefix</code>
+                        </td>
+                        <td>
+                            <code>"W"</code>
+                        </td>
+                        <td>
+                            string
+                        </td>
+                    </tr>
                     <tr>
                         <td>
                             <code>onItemClick</code>
diff --git a/js/jquery.fn.gantt.js b/js/jquery.fn.gantt.js
index 564f419..457ef51 100644
--- a/js/jquery.fn.gantt.js
+++ b/js/jquery.fn.gantt.js
@@ -180,6 +180,7 @@
             dow: ["S", "M", "T", "W", "T", "F", "S"],
             months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
             waitText: "Please wait...",
+            weekYearPrefix : "W",
             // navigation
             navigate: "buttons",
             scrollToToday: true,
@@ -435,6 +436,9 @@
                 var monthArr = [];
                 var scaleUnitsThisMonth = 0;
 
+                var woyArr = [];
+                var daysInWeek = 0;
+
                 var dayArr = [];
                 var hoursInDay = 0;
 
@@ -715,6 +719,7 @@
                     var dateBefore = ktkGetNextDate(range[0], -1);
                     year = dateBefore.getFullYear();
                     month = dateBefore.getMonth();
+					var weekOfYear = dateBefore.getWeekOfYear();
                     //day = dateBefore; // <- never used?
 
                     for (i = 0, len = range.length; i < len; i++) {
@@ -746,6 +751,21 @@
                         }
                         scaleUnitsThisMonth++;
 
+                        // Fill week of year
+                        if (rday.getWeekOfYear() !== weekOfYear) {
+                            // Fill weeks
+                            woyArr.push(
+                                    '<div class="row header weekyear" style="width:'
+                                    + tools.getCellSize() * daysInWeek
+                                    + 'px;"><div class="fn-label">'
+                                    + settings.weekYearPrefix + " " + weekOfYear +
+                            '</div></div>');
+
+                            weekOfYear = rday.getWeekOfYear();
+                            daysInWeek = 0;
+                        }
+                        daysInWeek++;
+
                         day = rday.getDay();
                         dayClass = dowClass[day];
                         if ( tools.isHoliday(rday) ) {
@@ -779,12 +799,20 @@
                         settings.months[month] +
                         '</div></div>');
 
+                    // Last week
+                    woyArr.push(
+                            '<div class="row header weekyear" style="width:'
+                            + tools.getCellSize() * daysInWeek
+                            + 'px;"><div class="fn-label">'
+                            + settings.weekYearPrefix +" " + weekOfYear + '</div></div>');
+
                     dataPanel = core.dataPanel(element, range.length * tools.getCellSize());
 
                     // Append panel elements
                     dataPanel.append(
                         $row.clone().html(yearArr.join("")),
                         $row.clone().html(monthArr.join("")),
+                        $row.clone().html(woyArr.join("")),
                         $row.clone().html(dayArr.join("")),
                         $row.clone().html(dowArr.join(""))
                     );
@@ -1140,7 +1168,7 @@
 
                                 // find row
                                 topEl = $(element).find("#rowheader" + i);
-                                top = tools.getCellSize() * 4 + 2 + topEl.data("offset");
+                                top = tools.getCellSize() * 5 + 2 + topEl.data("offset");
                                 _bar.css({ 'top': top, 'left': Math.floor(cFrom) });
 
                                 datapanel.append(_bar);
@@ -1231,7 +1259,7 @@
                     var headerRows = element.headerRows;
                     if (settings.scale === "hours" && scaleSt >= 13) {
                         scale = "days";
-                        headerRows = 4;
+                        headerRows = 5;
                         scaleSt = 13;
                     } else if (settings.scale === "days" && zoomIn) {
                         scale = "hours";
@@ -1247,7 +1275,7 @@
                         scaleSt = 14;
                     } else if (settings.scale === "weeks" && zoomIn) {
                         scale = "days";
-                        headerRows = 4;
+                        headerRows = 5;
                         scaleSt = 13;
                     } else if (settings.scale === "months" && zoomIn) {
                         scale = "weeks";
@@ -1742,7 +1770,7 @@
             case "days":
                 /* falls through */
             default:
-                this.headerRows = 4;
+                this.headerRows = 5;
                 this.scaleStep = 13;
             }