WordPress - get posts from beginning of time to 30 days in the future with custom meta date values. Useful for an events post type.

get_posts_and_future_posts.php

<?php

$upcoming_events = date( 'Ymd', strtotime( '+30 days' ) ); // Today + 30 days.

$events_args = array(
	'posts_per_page' => 10,
	'post_type' => 'event', //Events post type
	'post_status' => 'publish,future', //Also includes scheduled posts
	'orderby' => 'meta_value',
	'meta_key' => 'start_date',
	'order' => 'DESC',
	'meta_query' => array(
		array(
			//Get all event posts that have a start date less than or equal to 30 days from now
			'key' => 'start_date',
			'value' => array( '00000101', $upcoming_events), //Beginning of time to 30 days in future
			'type' => 'DATE',
			'compare' => 'BETWEEN'
		)
	)
);

//Events query
$events_query = new WP_Query( $events_args );