Hi nualexan ,
Please add this code snippet to functions.php file in your child theme directory, if you don’t have child theme configured, please follow this guide:
function eg_mod_query($query, $grid_id){
if($grid_id == 2){
$query['meta_query'] = array( 'key' => 'eg-date', 'value' => date("Y-m-d"), 'compare' => '>=', 'type' => 'DATE');
$query['meta_key'] = 'eg-date';
}
return $query;
}
Two things here you need to modify, the first one is the $grid_id
value, change this one to the Grid ID you have, please check this screenshot:

Secondly, the meta key name eg-date
, you must replace date
with your current custom field name.
Also, make sure to enter the date in YYYY-MM-DD formate in your custom field, for example: 2018-04-10
for today.
Check this guide as a reference.
Thanks.