public function getTimestamp( $style = TS_UNIX ) {
		if ( !isset( self::$formats[$style] ) ) {
			throw new TimestampException( __METHOD__ . ': Illegal timestamp output type.' );
		}

		$output = $this->timestamp->format( self::$formats[$style] );

		if ( $style == TS_RFC2822 ) {
			$output .= ' GMT';
		}

		if ( $style == TS_MW && strlen( $output ) !== 14 ) {
			throw new TimestampException( __METHOD__ . ': The timestamp cannot be represented in ' .
				'the specified format' );
		}

		return $output;
	}