Issue with setting custom metadata within a workflow

I need to create a custom activate later workflow. In order to accomplish that, I wrote a component dialog that allows the author to enter the date/time for the activate later to use.

<jcr:root xmlns:cq="http://www.day.com/jcr/cq/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0"
    jcr:primaryType="cq:Dialog"
    title="Activate Later"
    xtype="dialog">
    <items jcr:primaryType="cq:WidgetCollection">
        <actdatetime
            jcr:description="This is for creating responsive pages "
            jcr:primaryType="cq:Widget"
            fieldDescription="Indicate time and day"
            fieldLabel="Activation Date"
            name="./metaData/absoluteTime"
            xtype="datetime"/>
    </items>
</jcr:root>

I am using dialog participant step workflow component and referencing this dialog in the workflow. I am unable to save the absoluteTime field as metadata. Do you have any suggestions to save this? I can attach the workflow if it helps.

Thank you,
Banu