Adding seconds to a DateTime object in doctrine2 DQL

doctrine2_adding_seconds_to_datetime_dql.php

<?php
// in symfony2 app/ config.yml ...
doctrine:
    orm:
        entity_managers:
            default:
                dql:
                    datetime_functions:
                        unix_timestamp: Acme\AcmeBundle\DoctrineExtension\ORM\Query\AST\Functions\UnixTimestamp


// THEN, In a custom doctrine function file
//... SiteBundle\DoctrineExtension\ORM\Query\AST\Functions\UnixTimestamp.php
namespace Acme\AcmeBundle\DoctrineExtension\ORM\Query\AST\Functions;

use Doctrine\ORM\Query\Lexer;
use Doctrine\ORM\Query\SqlWalker;
use Doctrine\ORM\Query\Parser;

/**
 * UnixTimestampFunction ::= "UNIXTIMESTAMP" "(" ArithmeticPrimary ")"
 */
class UnixTimestamp extends \Doctrine\ORM\Query\AST\Functions\FunctionNode
{
	public $firstDateExpression = null;

	public function parse(Parser $parser)
	{
		$parser->match(Lexer::T_IDENTIFIER); // (2)
		$parser->match(Lexer::T_OPEN_PARENTHESIS); // (3)
		$this->firstDateExpression = $parser->ArithmeticPrimary(); // (4)
		$parser->match(Lexer::T_CLOSE_PARENTHESIS); // (3)
	}

	public function getSql(SqlWalker $sqlWalker)
	{
		return 'UNIX_TIMESTAMP(' .
		$this->firstDateExpression->dispatch($sqlWalker).
		')'; // (7)
	}
}



/// THEN, In your controller/Repository..
$now = new \DateTime("now",new \DateTimeZone('UTC'));

$QB = $this->createQueryBuilder('h');
$Query = $QB->where('h.dateLastCrawled IS NULL')
->orWhere($QB->expr()->sum( "UNIX_TIMESTAMP(h.dateLastCrawled)", 'h.revisitAfterSeconds')." <= UNIX_TIMESTAMP(:now)")
->setParameter(':now', $now)
->orderBy('h.revisitAfterSeconds', 'ASC')
->setFirstResult($batchOptions['offset'])
->setMaxResults($batchOptions['limit'])
->getQuery()
;
$result = $Query->getResult();

Updated the gist with a WORKING SOLUTION