delete-all-post-count-transients.php

<?php

function delete_all_post_count_transients() {
	$post_types = get_post_types();
	$years      = get_all_possible_years();
	$months     = get_all_possible_months();

	foreach ( $post_types as $post_type ) {
		foreach ( $years as $year ) {
			foreach ( $months as $month ) {
				$transient_key = "km_post_count_{$post_type}_{$year}_{$month}";

				delete_transient( $transient_key );
			}
		}
	}
}