Display only upcoming events in Wordpress widget

Hi. I’d like to modify the below code to only display upcoming (younger than the current date) events from my “Custom Post Type Events” in a Wordpress widget. At the moment it shows one of all event entries randomly.

This task is beyond my limited beginners PHP knowledge.

This is the date format I am using: j. M Y

<h2 style="margin-bottom:10px; margin-top:5px; color:#6b6b6b; text-align:left;">Veranstaltung:</h2>
  $args = array(

  $events=new WP_Query($args);

  while ($events->have_posts()) : $events->the_post(); 
    <?php the_field('f21_event_startdate'); ?>
    <h2><a style="color:#1e73be;" href="<?php the_permalink() ?>"><?php the_title(); ?></h2>
    <div style="margin-top:10px; margin-bottom: 10px;"><?php the_post_thumbnail('full'); ?></div></a>
    <b><?php the_field('f21_event_sub_header'); ?></b>
Sponsor our Newsletter | Privacy Policy | Terms of Service