Only show posts from the last trailing 12 months

This is how I did it in the end –

<?php
        $post_args = array(
            'post_type' => 'tribe_events',
            'eventDisplay'=>'custom',
            'start_date'     => date( 'Y-m-d H:i:s', strtotime( '-365 days' ) ),
            'tax_query' => array(

                array(
                    'taxonomy' => 'tribe_events_cat',
                    'field'    => 'slug',
                    'terms'    => 'management-leadership',
                    ),
                        ),

                        'meta_query' => array(
                            array(
                                'key' => 'associated_people',
                                'value' => $current_user,
                                'compare' => 'LIKE'
                        )
                    )
                ); ?>