The template to show our custom timeline using Wordpress and Advanced Custom Fields: http://jplhomer.org/2013/10/building-responsive-timeline-advanced-custom-fields/

page-about.php

<?php if ( $events = get_field( 'events' ) ) :
	// Re-order our events just in case
	if ( get_field('sort_order') == 'Date Descending') {
		usort( $events, 'sort_by_date_descending');
	} else {
		usort( $events, 'sort_by_date_ascending');
	}

	// Set a year checker to see if we should print a new year
	$year = 0;
	$is_new_year = false;
?>
<div class="timeline">
	<?php foreach ( $events as $idx => $event ) :

		$is_new_year = false;

		$event_year = date( "Y", strtotime( $event['event_date'] ) );

		if ( $year != $event_year ) {
			$year = $event_year;
			$is_new_year = true;
		}
	?>

	<?php if ( $is_new_year ) { ?>

		<?php if ( $idx > 0 ) { // If it's not the first event, we need to end the current list ?>
			</ul>
		<?php } ?>

		<h2><?php echo $event_year; ?></h2>

		<ul>
	<?php } ?>

	<li>
		<h3><?php echo $event['event_title']; ?></h3>

		<?php echo $event['event_description']; ?>

		<time><?php echo date( "F Y", strtotime($event['event_date']) ); ?></time>
	</li>

	<?php endforeach; ?>

	</ul>
</div>
<?php endif; ?>