Countdown Timer with Offset

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Fatal error: Uncaught TypeError: in_array(): Argument #2 ($haystack) must be of type array, null given in /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/plugins/t-countdown-control/admin/scripts/functions.php:40 Stack trace: #0 /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/plugins/t-countdown-control/admin/scripts/functions.php(40): in_array() #1 /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/plugins/t-countdown-control/admin/scripts/functions.php(267): schedulator() #2 /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/plugins/t-countdown-control/t-countdown-control.php(726): launchTarget() #3 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/shortcodes.php(355): WP_TMinusCountdown->shortcode() #4 [internal function]: do_shortcode_tag() #5 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/shortcodes.php(227): preg_replace_callback() #6 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/class-wp-hook.php(308): do_shortcode() #7 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/plugin.php(205): WP_Hook->apply_filters() #8 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/post-template.php(255): apply_filters() #9 /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/themes/twentyseventeen/template-parts/post/content.php(58): the_content() #10 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/template.php(785): require('...') #11 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/template.php(718): load_template() #12 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/general-template.php(204): locate_template() #13 /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/themes/twentyseventeen/single.php(24): get_template_part() #14 /var/www/vhosts/spacedonkey.de/httpdocs/wp-includes/template-loader.php(106): include('...') #15 /var/www/vhosts/spacedonkey.de/httpdocs/wp-blog-header.php(19): require_once('...') #16 /var/www/vhosts/spacedonkey.de/httpdocs/index.php(17): require('...') #17 {main} thrown in /var/www/vhosts/spacedonkey.de/httpdocs/wp-content/plugins/t-countdown-control/admin/scripts/functions.php on line 40