Last modified column in the posts list

<?php

add_action(
	'admin_init',
	static function () {
		foreach ( array( 'post', 'page' ) as $type ) {
			add_filter(
				"manage_{$type}_posts_columns",
				static function ( $columns ) {
					$columns['snipfire_modified'] = __( 'Last Modified' );
					return $columns;
				}
			);
			add_filter(
				"manage_edit-{$type}_sortable_columns",
				static function ( $columns ) {
					$columns['snipfire_modified'] = 'modified';
					return $columns;
				}
			);
			add_action(
				"manage_{$type}_posts_custom_column",
				static function ( $column, $post_id ) {
					if ( 'snipfire_modified' === $column ) {
						echo esc_html( get_the_modified_date( get_option( 'date_format' ) . ' ' . get_option( 'time_format' ), $post_id ) );
					}
				},
				10,
				2
			);
		}
	}
);