Wordpress shortcode to display a form 7 days before the event starts

functions.php

<?php

/**
 * Function that runs when the shortcode pf_show_event_form is called
 * @return string
 */
function pf_show_event_form() {
    if (!is_singular('event')){
        // This should only ever be called on a event page
        return '';
    }
    $no_entry_message = '<p> Ghaha, je bent te laat... Houdoe! </p> LOL, ik kan geen HTML... Success hiermee Daphne!';
    $gravityform_id = 1; // Dit moet je ff checken welk ID het is.
    $gravityform_title = false; //Check of je de title wilt weergeven
    $gravityform_desc = false; //Check of je de omschrijving wilt weergeven
    $gravityform_ajax = false; //Dit moet je ff checken of het een Ajax call moet zijn ja of nee
    $praktische_informatie = get_field('praktische_informatie', get_the_ID());
    $date_string = $praktische_informatie['datum'];
    
    $current = new \DateTime();
    $current->setTime(0,0,0);
    $future_date = clone $current;
    $future_date->modify('+7 days');
    $event_date = DateTime::createFromFormat( 'Ymd', $date_string );
    $event_date->setTime(0,0,0);
    if($event_date > $current && $event_date > $future_date) {
        return do_shortcode('[gravityform id="'.$gravityform_id.'" title="'.$gravityform_title.'" description="'.$gravityform_desc.'" ajax="'.$gravityform_ajax.'"]');
    }
    return $no_entry_message;
}

/**
 * Register the shortcode
 */
add_shortcode('pf_show_event_form', 'pf_show_event_form');