I used HealthCheck & Troubleshooting and discovered that I had this in my child theme’s functions.php (I don’t remember why…). I removed it and saved dates are back !
// acf date format
function acf_smart_dates($field) {
if ($field[‘value’]) {
$field[‘value’] = date(‘d/m/Y’,strtotime($field[‘value’]));
}
return $field;
}
add_filter(‘acf/prepare_field/type=date_picker’,’acf_smart_dates’);