ServiceProvider.php

<?php

namespace TransformStudios\Events;

use Statamic\Facades\Collection;
use Statamic\Facades\Field;
use Statamic\Providers\AddonServiceProvider;
use Statamic\Statamic;

class ServiceProvider extends AddonServiceProvider
{
    public function bootAddon()
    {
        Field::computedDefault('default-events-timezone', fn () => Statamic::displayTimezone());
        Field::computedDefault('default-event-timezone', fn () => Events::defaultTimezone());

        // has to be in booted so that the `events::event` fieldset is properly registered and loaded
        $this->booted(function () {
            collect(Events::setting('collections', ['events']))
                ->each(function (string $collection) {
                    Collection::findByHandle($collection)?->entryBlueprint()->ensureField(
                        'timezone',
                        [
                            'dictionary' => 'timezones',
                            'max_items' => '1',
                            'type' => 'dictionary',
                            'default' => 'computed:default-event-timezone',
                        ]);
                });
        });
    }
}