Replace “Howdy” text in WordPress backend

WordPress welcomes a user in the English version of the backend with Howdy, [user] in the top right corner.
Replace it with a more formal “Welcome”.
Or “RTFM before asking me” for that loved one you’re making a free website for…

function replace_howdy( $wp_admin_bar ) {
	$my_account = $wp_admin_bar->get_node( 'my-account' );
	$newtitle = str_replace( 'Howdy,', 'Welcome,', $my_account->title );
	$wp_admin_bar->add_node( 
		array(
			'id' => 'my-account',
			'title' => $newtitle,
		) 
	);
}
add_filter( 'admin_bar_menu', 'replace_howdy', 25 );