WordPress - Show Only Future Posts/Events

snippet.php

<?php
// Usage: Example below makes the CPT archive "Events" show all upcoming events only, and order by soonest->latest
// Make sure to change the 'key' to your meta_value that has the post ID (you can use future posts but that can cause other problems)

function show_upcoming_events( $query ) {
	if ( is_admin() || ! $query->is_main_query() ) {
		return;
	}

	if ( is_post_type_archive( 'events' )) {
		$query->set( 'posts_per_page','-1');
		$query->set( 'meta_query', array(
			array(
				'key' 	=> '_date_event',
				'compare' 	=> '>=',
				'value' 	=> date('Ymd')
			)
		));
		$query->set( 'meta_key', '_date_event' );
		$query->set( 'orderby', 'meta_value' );
		$query->set( 'order', 'ASC' );
		return;
	}
}
add_filter( 'pre_get_posts', 'show_upcoming_events' );