I am having the following issue on date fields on subsites. the weird thing is that in root site the date picker just works fine.
These date fields are provisioned with xml site columns, there is nothing special on them
<Field
ID="{99E2FB9E-4DBD-4BCA-B1DE-7016C814D966}"
Name="xxx_ApprovalDate"
StaticName="xxx_ApprovalDate"
DisplayName="$Resources:xxx,sitecolumns_client_approvalDate_displayName;"
Type="DateTime"
Format="DateOnly"
Required="FALSE"
Group="$Resources:xxx,sitecolumns_fieldgroup;">
<Default>[today]</Default>
</Field>
EDIT:
I think I have nailed it down to be a problem in the custom master page, our custom master page is a copy of seattle.master, however with a small jquery script to render the navigation menu on a separate search center
I guess this script is causing this:
<script type="text/javascript">
$(document).ready(function() {
if ($('.ms-searchCenter-refinement').length > 0) {
// Unhide the title row
$('#s4-titlerow').attr('style', 'display:block !important');
// Set the Site Title
$('#DeltaPlaceHolderPageTitleInTitleArea').text('Search Center');
// Hide the search icon
$('#searchIcon').hide();
// Remove the top margin
$('.ms-searchCenter-refinement').css('margin-top', '0');
// The following line is only needed for firefox
$('body').append('<style>#s4-titlerow { display: block !important; }</style');
}
});
</script>