itemprop datemodified

Hi,

I wanted to display last date when i modified a post and itemprop=”dateModified”, so i modified loop-index file and wrote that:

echo "<time class='date-container minor-meta updated' $markup>".get_the_time(get_option('date_format'))."</time>";
				if (get_the_modified_time() != get_the_time()) {
				echo ", ";
				echo "<time class='date-container minor-meta updated' itemprop='dateModified' datetime=".get_the_modified_time('c')."> last modified ".get_the_modified_time(get_option('date_format'), $the_id)."</time>";
               	}

It works great but i don’t know if it’s optimal for page speed. I’m not developper, so I ask you some advice or a better solution to implement that

Thanks