diff --git a/addons/web_gantt/static/src/js/gantt.js b/addons/web_gantt/static/src/js/gantt.js
index 04f1ad0835e..0763a2eb059 100644
--- a/addons/web_gantt/static/src/js/gantt.js
+++ b/addons/web_gantt/static/src/js/gantt.js
@@ -138,8 +138,8 @@ openerp.web_gantt.GanttView = openerp.web.View.extend({
                 }
                 var duration = (task_stop.getTime() - task_start.getTime()) / (1000 * 60 * 60);
                 if (task.id == 23)
-                    console.log("loading", task.id, task_start.toString(), task_start.clone().addMilliseconds(duration * 60 * 60 * 1000).toString());
-                var task_info = new GanttTaskInfo(_.uniqueId(), task_name, task_start, duration, 100);
+                    console.log("loading", task.id, task_start.toString(), duration, task_start.clone().addMilliseconds(duration * 60 * 60 * 1000).toString());
+                var task_info = new GanttTaskInfo(_.uniqueId(), task_name, task_start, ((duration / 24) * 8), 100);
                 task_info.internal_task = task;
                 return {task_info: task_info, task_start: task_start, task_stop: task_stop};
             }
@@ -162,8 +162,8 @@ openerp.web_gantt.GanttView = openerp.web.View.extend({
         var self = this;
         var itask = task_obj.TaskInfo.internal_task;
         var start = task_obj.getEST();
-        var end = task_obj.getFinishDate();
-        var duration = (end.getTime() - start.getTime()) / (1000 * 60 * 60);
+        var duration = (task_obj.getDuration() / 8) * 24;
+        var end = start.clone().addMilliseconds(duration * 60 * 60 * 1000);
         console.log("saving", itask.id, start.toString(), end.toString());
         var data = {};
         data[self.fields_view.arch.attrs.date_start] =