Default value format for the CQ datetime widget

Hi,

I have created a simple dialog.xml with datetime property:

<firstReplicate

            jcr:primaryType="cq:Widget"

            fieldLabel="Article Date:"

            name="./firstReplicated"

            xtype="datetime"/>

Now, in the documentation: we see that this widget accepts

data : Mixed

The initial set of data to apply to the tpl to update the content area of the Component.

<firstReplicate

            jcr:primaryType="cq:Widget"

            fieldLabel="Article Date:"

            data="2013-07-18T00:45:00.000+01:00"

            name="./firstReplicated"

            xtype="datetime"/>

Didn't seem to be setting the data value on my datetime. What is the correct data value for the datetime xtype ?

Thanks,

Peter