Creating a new node with the finders_event_date field fails.

I've installed finders and finders_events on an existing site, and upgraded localgov_events from 3.x to 4.x. As there's no upgrade path for localgov_events yet, I had to re-do the existing configuration for it in the UI.

When trying to create my first event node, the node form page failed with:

The website encountered an unexpected error. Try again later.

DateInvalidTimeZoneException: DateTimeZone::__construct(): Unknown or bad timezone () in DateTimeZone->__construct() (line 25 of modules/contrib/date_recur/src/Plugin/Field/DateRecurDateTimeComputed.php).
Drupal\date_recur\Plugin\Field\DateRecurDateTimeComputed->getValue() (Line: 154)
Drupal\Core\Field\FieldItemBase->__get() (Line: 154)
Drupal\date_recur_modular\Plugin\Field\FieldWidget\DateRecurModularAlphaWidget->formElement() (Line: 459)
Drupal\Core\Field\WidgetBase->formSingleElement() (Line: 219)
Drupal\Core\Field\WidgetBase->formMultipleElements() (Line: 120)
Drupal\Core\Field\WidgetBase->form() (Line: 190)
Drupal\Core\Entity\Entity\EntityFormDisplay->buildForm() (Line: 121)
Drupal\Core\Entity\ContentEntityForm->form() (Line: 134)
Drupal\node\NodeForm->form() (Line: 107)
Drupal\Core\Entity\EntityForm->buildForm()
call_user_func_array() (Line: 536)
Drupal\Core\Form\FormBuilder->retrieveForm() (Line: 284)
Drupal\Core\Form\FormBuilder->buildForm() (Line: 73)
Drupal\Core\Controller\FormController->getContentResult()
call_user_func_array() (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 121)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 116)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 90)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741)
Drupal\Core\DrupalKernel->handle() (Line: 23)

The timezone is set on the field definition though. I stepped through the code to find why the tz value is missing, and eventually got to this point in field_recur, where the default value is set on a newly created node: https://git.drupalcode.org/project/date_recur/-/blob/3.9.x/src/Plugin/Fi...

The default timezone is only used if requested. IE, if default_time_zone_source is set to DateRecurFieldItemList::DEFAULT_TIME_ZONE_SOURCE_FIXED.

I'm going to add this to the field that this module creates and see if it helps.