Utility functions and a sample widget to display the next event

wp-events-widgets.php

<?php 
function events_get_next_event() {
	global $wpdb;
	
	$events_table = $wpdb->prefix . 'events';
	$date_now = current_time('timestamp');

	$query = $wpdb->prepare("SELECT * FROM $events_table WHERE thetime > %s ORDER BY thetime ASC LIMIT 1", $date_now);
	$event = $wpdb->get_row($query);
	
	if( !$events || is_wp_error( $event ) )
		return false;
	
	return $event;
}

function events_get_last_event() {
	global $wpdb;
	
	$events_table = $wpdb->prefix . 'events';
	$date_now = current_time('timestamp');
	
	$query = $wpdb->prepare("SELECT * FROM $events_table WHERE thetime < %s ORDER BY thetime DESC LIMIT 1", $date_now);
	$event = $wpdb->get_row($query);
	
	if( !$events || is_wp_error( $event ) )
		return false;
	
	return $event;
}

function events_get_current_event() {
	global $wpdb;
	
	$events_table = $wpdb->prefix . 'events';
	$date_now = current_time('timestamp');
	$query = $wpdb->prepare("SELECT * FROM $events_table WHERE thetime > %s AND theend < %s ORDER BY thetime ASC LIMIT 1", $date_now, $date_now);
	
	$event = $wpdb->get_row($query);
	
	if( !$events || is_wp_error( $event ) )
		return false;
	
	return $event;
}

wp_register_sidebar_widget( 'events_next_event', 'Next Event', 'events_next_event_widget' );

function events_next_event_widget() {
	$event = events_get_next_event();
	
	if($event) {
		?>
			<h4><?php echo $event->title; ?></h4>
		<?php
	}
}
?>