Countries sometimes change their laws pertaining to time zones and daylight saving times. This means that GMT+2 can be a different local time this August compared to last August! It could even be a different date!
In a nutshell, the task at hand is to mark (or render) a model attribute in the typical "_form.php" view file with the 'required' red asterisk while this attribute is not marked as required in the model's rule() method.
If you're interested only in the solution, jump ahead to the 'solution' section below.