Do you want it to appear like that in InfoPath or in SharePoint? If its InfoPath, you'll have to use substrings to get the specific format you want if its not one of the out of box formats in the format date properties dialog. If its SharePoint, you could try and use a calculated column but to be honest not sure if that will 100% work for you. Just keep in mind that if you set it one way in InfoPath it doesn't mean that it will be reflected the same way in SharePoint. You are simply changing how its displayed in the control via InfoPath. The field data itself isn't being changed, so that means it won't get reflected in SharePoint. Hope this helps,
Anson Hidajat
Qdabra® Software/ InfoPathDev.comThe InfoPath Experts – Streamline data gathering to turn process into knowledge.™