Exception in 'HTTP JSON API' task

[aspergarus]

There is an exception genereted by

new DateTime($iso);

We should set the default timezone. However, the issue is in the solution.php, and we can't pass this task unless we edit it.
Could you please fix it for the following users?

[AydinHassan]

We do actually set the timezone, we patch each solution on the fly, but we set it to Europe/London as we don't really know what timezone the user is in and it might not be set.

It is set here: https://github.com/php-school/php-workshop/blob/master/app/config.php#L204

Do you have any suggestions on how to fix it?