PHP: query with parameter for SET

Hi everyone,

Using PHP (or indeed maybe more generally), is it possible to issue a 
SET TIME ZONE statement with a parameter for the new runtime setting?

In a PHP application I'm issuing a SET TIME ZONE command just after the 
database connection is created, and for security I'd like to pass the 
time zone value in a parameter, as it's coming from a configuration file 
- something like this:

     $pdo = new PDO(/* DSN goes here */);

     $statement = $pdo->prepare('set time zone :tz');
     $statement->execute([':tz' => 'Europe/Dublin']);

However, in the logs I see:

ERROR:  syntax error at or near "to" at character 15
STATEMENT:  set time zone $1

Is this possible? I've also tried the "set timezone ..." variant with 
similar results. I'm wondering too if the limitation (if such it is) is 
in PHP or whether it's a Postgres thing.

Thanks,

Ray.

-- 
Raymond O'Donnell // Galway // Ireland
ray@rodonnell.ie