Date update

Hello I’m trying to update the gantt date with javascript but i have an error.
I initialize the gantt with XML and is showed ok “<start_date></start_date>”
But when i update it with javascript i have 2 cases:

var task = gantt.getTask(id);
task.start_date= “29/04/2015”–> if i put this, the gantt is formatted on the grid ok but on the gantt is moved to the limit and is not showed
task.start_date= new Date(); --> if i put this, the gantt is showed ok, but on the grid lost the format and is showed as " Wed Apr 29 2015 00:00:00 GMT-0300".

Wich is the format to set the date and keep my format?
Thanks in advance.


var task = gantt.getTask(id); task.start_date= "29/04/2015" The start_date/end_date properties must receive a Date object as a value.
The dates should be displayed correctly, you can check the example

The issue must be caused by a custom column templates that specified in your code. Please provide a link to some kind of demo

Is really a strange case, because object seems on same state, but this is my analysis.
On our app we have a dhtmlxWindow, i’m sending the object ganttTask by window to the popup, and if I modify the fields on the popup, it work KO. but if I modify directly on the screen is OK.
Really strange because the object when I’m going to made the “updateTask” is on the same state the fields.
I need to declare, the “updateTask” is madding on callback of the popup always.