Great wonderful!
Thank you so kimipooh!
I ended up with this (not sure its the right way but works fine):
shortcode:
[gc_list_view date_format="d-m-Y H.i" hook_secret_key="*****" orderbysort="ascending"]
functions.php:
add_filter( 'lvgc_each_output_data' , 'lvgc_each_output_data_fix' , 10 , 2 );
function lvgc_each_output_data_fix($out, $out_atts){
extract($out_atts);
$hook_secret_key = '*****';
$startdate = substr($start_date_value, 0, 10);
$start_date_value_timestamp = strtotime($start_date_value);
$dayname = substr(date_i18n("l",$start_date_value_timestamp), 0, 2);
$starttime = substr($start_date_value, 11, 5);
$endtime = substr($end_date_value, 11, 5);
$out = <<< ___EOF___
<li class="${html_tag_class}_item"><span class="${html_tag_class}_date">$startdate</span> <span class="${html_tag_class}_dayname">($dayname)</span> <span class="${html_tag_class}_time">$starttime - $endtime</span> $output_category_temp <a class="${html_tag_class}_link" href="$gc_link" target="_blank">$gc_title</a></li>
___EOF___;
return array('hook_secret_key'=>$hook_secret_key, 'data'=>$out);
}