Views date fielter plugin alter

mydate.info.yml

name: My date
description: "Overrides core date views filter"
type: module
package: "Views"
core_version_requirement: '>=8.8.0'

mydate.module

<?php

// overrides views date plugin
use Drupal\mydate\Plugin\views\filter\MyDate;

/**
 * Implements hook_views_plugins_filter_alter().
 */
function mydate_views_plugins_filter_alter(array &$plugins) {
  // Change the 'date' handler class.
  $plugins['date']['class'] = MyDate::class;
}

src\Plugin\views\filter\MyDate.php

<?php

namespace Drupal\mydate\Plugin\views\filter;

use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Plugin\views\filter\Date;

/**
 * Filter to handle dates stored as a timestamp, extended by "aday" option.
 *
 * @ingroup views_filter_handlers
 */
class MyDate extends Date {

  /**
   * {@inheritdoc}
   */
  protected function valueForm(&$form, FormStateInterface $form_state) {
    parent::valueForm($form, $form_state);
    if (isset($form['value']['type']['#options'])) {
      $form['value']['type']['#options']['aday'] = $this->t('One day');
    }
  }

  /**
   * {@inheritdoc}
   */
  protected function opSimple($field) {
    if ($this->value['type'] === 'aday') {
      $value = $this->value['value'];
      // @todo Convert input to unixtime in UTC timezone and use between or
      //   (field  > $a and $field < $b) where a and b are daily bounds.
      $this->query->addWhereExpression($this->options['group'], "$field $this->operator $value");
    }
    else {
      parent::opSimple($field);
    }
  }

}