Expire a particular WordPress users session everyday at midnight

destroy_user_session_cron.php

<?php
$time = my_strtolocaltime( 'midnight' );
my_schedule_cron( 'my_destroy_sessions_cron', 'daily', $time );
add_action( 'my_destroy_sessions_cron', 'my_destroy_sessions' );

/**
 * Destroy all sessions for guest user.
 *
 * @return void
 */
function my_destroy_sessions(){
	// Grabs userdata by the username.
	$user = get_user_by( 'login', 'guest' );
	if( $user ) {
	  // get all sessions for user with ID $user_id
    $sessions = WP_Session_Tokens::get_instance($user->ID);

    // we have got the sessions, destroy them all!
    $sessions->destroy_all();
  }
}

/**
 * Works much like strtotime() but uses the timezone setting in WordPress
 * in order to convert it to localtime.
 *
 * @param  string $str  String to convert into time.
 * @return int          Unix time reflecting corresponding local time.
 */
function my_strtolocaltime( $str ){
	if( '' !== get_option('timezone_string') ){
		$tz = timezone_open( get_option( 'timezone_string' ) );
		$now = new DateTime( "now", timezone_open ( '+0' ) );
		$offset = timezone_offset_get(  $tz ,  $now );
	}
	else{
		$offset = get_option( 'gmt_offset' ) * HOUR_IN_SECONDS;
	}
	$time = strtotime($str) - $offset;
	return $time;
}

/**
 * Schedule cron Job.
 *
 * @static
 * @param  string $hook        : Hook to use for cron event.
 * @param  string $recurrence  : Cron recurrence period. i.e. daily, monthly, etc.
 * @param  int    $time        : Time to execute cron.
 */
function my_schedule_cron( $hook, $recurrence = null, $time = null ) {
	// If reccurence and time not sent, then set defaults.
	$recurrence = $recurrence ?? 'daily';
	$time = $time ?? time();
	// Schedule.
	if ( ! wp_next_scheduled( $hook ) ) {
		wp_schedule_event( $time, $recurrence , $hook );
	}
}