Datepicker exposed filter with Apachesolr view fields

Hi,

I have a case where implementation of faceted solr search inside a view should be integrated, date range should be picked up by jquery popup calendar. I have apachesolr views installed with BEF and all required dependencies. I'm facing issues with the jquery calendar. Input fields are from type textfield and filtration is working properly but for some reason jquery calendar is not appearing on the front end. From BEF settings I picked up jquery calendar option for these fields and in the code I see that bef module is attaching bef-datepicker class to the field attributes values. However when the form output code is generated after

$output = drupal_render($form);

I dont see bef-datepicker class at all. Has someone faced similar issues?