<?php

function facetwp_translate_text( $translated_text, $text, $domain ) {
    if ( 'fwp' == $domain ) {
        if ( 'Start Date' == $translated_text || 'End Date' == $translated_text ) {
            return '';
        }
    }
    return $translated_text;
}
add_filter( 'gettext', 'facetwp_translate_text', 10, 3 );