Could you please enable debug mode in the global configuration and repeat the steps you took above and then post the stack trace that will be output.

@brianteeman Below are the debugging errors:

     0 Call to a member function format() on bool 

Call stack
# 	Function 	                                               Location
1 	() 	                                                       JROOT/libraries/src/Form/Field/CalendarField.php:352
2 	Joomla\CMS\Form\Field\CalendarField->filter() 	               JROOT/libraries/src/Form/Form.php:1047
3 	Joomla\CMS\Form\Form->filter() 	                               JROOT/libraries/src/Form/Form.php:991
4 	Joomla\CMS\Form\Form->process() 	                       JROOT/libraries/src/MVC/Model/FormModel.php:213
5 	Joomla\CMS\MVC\Model\FormModel->validate() 	               JROOT/libraries/src/MVC/Controller/FormController.php:623
6 	Joomla\CMS\MVC\Controller\FormController->save() 	       JROOT/libraries/src/MVC/Controller/BaseController.php:672
7 	Joomla\CMS\MVC\Controller\BaseController->execute() 	       JROOT/libraries/src/Dispatcher/ComponentDispatcher.php:143
8 	Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch() 	       JROOT/libraries/src/Component/ComponentHelper.php:355
9 	Joomla\CMS\Component\ComponentHelper::renderComponent()        JROOT/libraries/src/Application/AdministratorApplication.php:143
10 	Joomla\CMS\Application\AdministratorApplication->dispatch()    JROOT/libraries/src/Application/AdministratorApplication.php:186
11 	Joomla\CMS\Application\AdministratorApplication->doExecute()   JROOT/libraries/src/Application/CMSApplication.php:294
12 	Joomla\CMS\Application\CMSApplication->execute() 	       JROOT/administrator/includes/app.php:61
13 	require_once() 	                                               JROOT/administrator/index.php:32 

Thanks for that.

I have confirmed the issue in Polish but not in other languages and it is with all calendar fields not just the one in user notes

As soon as I finish my coffee I will investigate further. I have a pretty good idea of where the problem is so it shouldnt take long

Found the problem - its a language string in the polish language pack that is not correct

DATE_FORMAT_FILTER_DATE = d-m-y
DATE_FORMAT_FILTER_DATETIME = Y-m-d H:i:s

The date format filter date needs to be in the same order as the datetime filter

If you create a language override for DATE_FORMAT_FILTER_DATE and set it to Y-m-d then it will work correctly

@tecpromotion something to inform the polish tt about

@brianteeman @Valdnet Described issue has been fixed in version 4.2.2v3 of Polish language pack with is available on https://downloads.joomla.org/language-packs/translations-joomla4/downloads/joomla4-polish/4-2-2-3 and will be available as an update.

@Valdnet can you close this issue as solved?

@brianteeman @wojsmol @max123kl After updating to version 4.2.2v3 of the Polish language, the problem still occurs with the date.

confirming the problem is not fixed

I noticed that in the new version 2.2.2v3 for the Polish language, the date format has not been changed according to @brianteeman instructions.

Manual editing of files and code changes:

DATE_FORMAT_FILTER_DATE="d-m-y"
DATE_FORMAT_FILTER_DATETIME="d-m-y H:i:s"

on

DATE_FORMAT_FILTER_DATE="Y-m-d"
DATE_FORMAT_FILTER_DATETIME="Y-m-d H:i:s"

ini files solves the problem.

@wojsmol is the installation package properly added?

@Valdnet @brianteeman Please post your php version.

in light of something I just saw in the language pack I withdraw from this conversation

in light of something I just saw in the language pack I withdraw from this conversation

@brianteeman What do you mean? You can message me on Mattermost.

Please post your php version.

@wojsmol My PHP version is 7.4

@brianteeman You found an easteregg ? Congrats ? I bet there are more of them........
@Valdnet just update to php:latest

Now that v4 of the language pack has been released I can confirm the issue is now solved and this can be closed

Works great. Thanks a lot for the fix ?.