Change the entry date with a new meta box in the entry details page.

gr-change-entry-date-metabox.php

<?php
/**
 * Plugin Name: Gravity Forms Change Entry Date
 * Plugin URI: https://gravityranger.com/gravity-forms-changing-the-entry-date
 * Description: Adds a meta box to Gravity Forms entry details page allowing admins to change the entry date.
 * Version: 1.0
 * Author: Chris Eggleston
 * Author URI: https://gravityranger.com
 * License: GPL-2.0+
 */

if (!defined('ABSPATH')) {
    exit; // Prevent direct access
}

// Add Meta Box to Entry Details Page
add_filter('gform_entry_detail_meta_boxes', function ($meta_boxes, $entry) {
    $meta_boxes['update_entry_date'] = [
        'title'    => 'Change Entry Date',
        'callback' => 'gf_render_entry_date_meta_box',
        'context'  => 'normal',
    ];
    return $meta_boxes;
}, 10, 2);

function gf_render_entry_date_meta_box($args) {
    $entry_id = rgget('lid'); // Get entry ID from URL

    if (!$entry_id) {
        echo '<div class="notice notice-error"><p>Invalid entry ID.</p></div>';
        return;
    }

    $entry = GFAPI::get_entry($entry_id); // Fetch entry

    if (is_wp_error($entry) || empty($entry) || !isset($entry['date_created'])) {
        echo '<div class="notice notice-error"><p>Invalid entry data.</p></div>';
        return;
    }

    $current_date = $entry['date_created'];
    $current_date_only = date('Y-m-d', strtotime($current_date));
    $current_time_only = date('H:i:s', strtotime($current_date));

    ?>
    <div style="padding: 10px;">
        <?php if (isset($_GET['update_success']) && $_GET['update_success'] == '1') : ?>
            <div class="notice notice-success">
                <p>Entry date updated successfully.</p>
            </div>
        <?php endif; ?>
        <form method="post" style="margin-top: 20px;">
            <p><strong>Current Date:</strong> <?php echo esc_html($current_date); ?></p>
            <p>
                <label for="new_entry_date"><strong>New Date (YYYY-MM-DD):</strong></label>
                <input type="text" id="new_entry_date" name="new_entry_date" value="<?php echo esc_attr($current_date_only); ?>" style="width: 100%; max-width: 300px;">
            </p>
            <?php wp_nonce_field('update_entry_date', 'update_entry_date_nonce'); ?>
            <p>
                <input type="submit" name="update_entry_date_submit" class="button button-primary" value="Update Date">
            </p>
        </form>
    </div>
    <?php

    // Handle Form Submission
    if (isset($_POST['update_entry_date_submit'])) {
        gf_handle_entry_date_update($entry_id, $current_time_only);
    }
}

function gf_handle_entry_date_update($entry_id, $current_time_only) {
    // Verify Nonce
    if (!isset($_POST['update_entry_date_nonce']) || !wp_verify_nonce($_POST['update_entry_date_nonce'], 'update_entry_date')) {
        echo '<div class="notice notice-error"><p>Security check failed.</p></div>';
        return;
    }

    $new_date_only = sanitize_text_field($_POST['new_entry_date']);

    // Validate New Date Format
    if (DateTime::createFromFormat('Y-m-d', $new_date_only) === false) {
        echo '<div class="notice notice-error"><p>Invalid date format. Use YYYY-MM-DD.</p></div>';
        return;
    }

    // Combine New Date with Original Time
    $new_date = $new_date_only . ' ' . $current_time_only;

    // Update Entry Date
    $result = GFAPI::update_entry_property($entry_id, 'date_created', $new_date);

    if (is_wp_error($result)) {
        echo '<div class="notice notice-error"><p>Error updating entry date: ' . esc_html($result->get_error_message()) . '</p></div>';
    } else {
        // Redirect to avoid form resubmission
        $redirect_url = add_query_arg(['update_success' => '1'], remove_query_arg(['update_success']));
        wp_safe_redirect($redirect_url);
        exit;
    }
}