Wordpress ACF datepicker fields not working - php

Question

I created a "vacations" custom-post-type in which there are two custom fields -> "startdate" and "enddate". The field types are both "Date Picker" obviously.
But for some reason I dont know, I'm not able to fetch these fields. It returns nothing or null.
In my functions.php I have this:
function get_vacation_dates(){
$startDate = get_field('vacation_start', false, false);
$endDate = get_field('vacation_end', false, false);
$start_date = new DateTime($startDate);
$end_date = new DateTime($endDate);
$args = array(
'post_type' => array('ferieperioder'),
'post_status' => array('publish'),
'posts_per_page' => -1,
'post__in' => $post->ID,
'meta_key' => array(
'key' => 'vacation_start',
'value' => $startDate
),
array(
'key' => 'vacation_end',
'value' => $endDate
)
);
$query = new WP_Query($args);
echo json_encode($query);
die();
}
add_action('wp_ajax_nopriv_get_vacation_dates', 'get_vacation_dates');
add_action('wp_ajax_get_vacation_dates','get_vacation_dates');
I don't know if this is correct at all, since I want to get each vacation_period (there can be multiple "vacation"-posts) returned as json for some AJAX-handling.
For example I want an json array like this:
[ {
"vacation_name" : "summer",
"vacation_start" : "01-07-2019",
"vacation_end" : "30-07-2019"
},
{
"vacation_name" : "winter",
"vacation_start" : "01-12-2019",
"vacation_end" : "14-12-2019"
},
]
or something like that...
How can I achieve that?

Answer 1

I think you should do it with meta_query like this:
$args = array(
'post_type' => array('ferieperioder'),
'post_status' => array('publish'),
'posts_per_page' => -1,
'post__in' => $post->ID,
'meta_query' => array(
'relation' => 'AND',
array(
'key' => 'vacation_start',
'value' => $startDate,
'type' => 'DATE',
'compare' => '>='
),
array(
'key' => 'vacation_end',
'value' => $endDate,
'type' => 'DATE',
'compare' => '<='
)
)
);