wp args order by multiple columns
"post_type" => "event",
"post_status" => "publish",
"posts_per_page" => 25,
"ignore_sticky_posts" => 0,
"show_sticky" => true,
"meta_query" => array(
"event_start_date" => array(
"key" => "_meta_event_start_date",
"compare" => ">=",
"value" => 0
),
"event_start_time" => array(
"key" => "_meta_event_start_time",
"compare" => ">=",
"value" => 0
)
),
"orderby" => array(
"event_start_date" => "ASC",
"event_start_time" => "ASC"
)