Visitor Local Event Times

<?php
/**
 * Allows you to display local times on web pages (not emails etc.) relative to the user's browser time settings using 4 new placeholders similar to the placeholders showing 24/12 hour time formats:
 *
 * #_12HSTARTTIMELOCAL, #_12HENDTIMELOCAL, #_24HSTARTTIMELOCAL and #_24HENDTIMELOCAL
 * This is purely determined by the user's browser settings and results may vary according to browser version.
 *
 * Another option is to generate links in formatting which point to a third party service, for example:
 *  <a href="https://www.thetimezoneconverter.com/?t=#h%3A#i%20#a&tz=#_LOCATIONTOWN" target="_blank">See local time</a>
 * Note that in this case for this website, the link depends on the fact that a valid city name is provided.
 *
 * For installation instructions, see here - http://wp-events-plugin.com/tutorials/how-to-safely-add-php-code-to-wordpress/
 *
 * @param string $replace
 * @param EM_Event $EM_Event
 * @param string $result
 * @return string
 */
function my_em_event_local_time_placeholders($replace, $EM_Event, $result){
    switch( $result ){
        case '#_12HSTARTTIMELOCAL':
        case '#_12HENDTIMELOCAL':
            $rand = rand();
            $ts = ($result == '#_12HSTARTTIMELOCAL') ? $EM_Event->start()->getTimestamp():$EM_Event->end()->getTimestamp();
            ob_start();
            ?>
            <span id="em-start-local-time-<?php echo $rand ?>">Enable JS to see time...</span>
            <script>
                var date = new Date(<?php echo $ts * 1000 ?>);
                var hours = date.getHours();
                var minutes = date.getMinutes();
                var ampm = hours >= 12 ? 'PM' : 'AM';
                hours = hours % 12;
                hours = hours ? hours : 12; // the hour '0' should be '12'
                minutes = minutes < 10 ? '0'+minutes : minutes;
                var strTime = hours + ':' + minutes + ' ' + ampm;
                document.getElementById("em-start-local-time-<?php echo $rand ?>").innerHTML = strTime;
            </script>
            <?php
            $replace = ob_get_clean();
            break;
        case '#_24HSTARTTIMELOCAL':
        case '#_24HENDTIMELOCAL':
            $rand = rand();
            $ts = ($result == '#_24HSTARTTIMELOCAL') ? $EM_Event->start()->getTimestamp():$EM_Event->end()->getTimestamp();
            ob_start();
            ?>
            <span id="em-start-local-time-<?php echo $rand ?>">Enable JS to see time...</span>
            <script>
                var date = new Date(<?php echo $ts * 1000 ?>);
                var hours = date.getHours();
                var minutes = date.getMinutes();
                hours = hours < 10 ? '0' + hours : hours;
                minutes = minutes < 10 ? '0' + minutes : minutes;
                document.getElementById("em-start-local-time-<?php echo $rand ?>").innerHTML = hours + ':' + minutes;
            </script>
            <?php
            $replace = ob_get_clean();
            break;
    }
    return $replace;
}
add_filter('em_event_output_placeholder','my_em_event_local_time_placeholders',1,3);