Ok I sorted it out myself. You need to use named meta query.
<?php // Meta query for tab
$current_date = date('Ymd');
$future_date = date('Ymd', strtotime('+6 days'));
$args = [
'post_type' => 'events',
'post_status' => 'publish',
'posts_per_page' => 12,
'meta_query' => array(
'relation' => 'AND',
'date_meta' => array(
'key' => 'event_date',
'value' => [$current_date, $future_date], // Use an array to specify a range
'compare' => 'BETWEEN', // Use BETWEEN to specify a range
'type' => 'DATE',
),
'time_meta' => array(
'key' => 'start_at', // 'start_at' is the custom field storing the time value
'type' => 'TIME' // Use 'TIME' meta type for 'start_at' field
),
),
'orderby' => [
'date_meta' => 'ASC', // Order by 'event_date' in ascending order
'time_meta' => 'ASC' // Then order by 'start_at' in ascending order
]
];
include(locate_template('template-parts/tabs-inner-include.php', false, false));
?>
