add_action('admin_menu','tictac_admin_menu_option');

function tictac_admin_menu_option()
{
  add_menu_page(
  'Gestion des Horaires',
  'Time Control',
  'manage_options',
  'tictac_admin_menu',
  'tictac_scripts_page',
  //plugins_url( 'time-control/admin/logo/tictac-logo.png' ),
  'dashicons-calendar-alt'
  //16
  );
  add_submenu_page('tictac_admin_menu',
  'Sous menu Opening',
  'Options Opening',
  'tictac_admin_submenu',
  'tictac_scripts_menu',
  'tictac_opening_submenu'
  );

}
function tictac_opening_submenu()
{
  ?>
  <div id="wrap">
    <h1>Add Opening</h1>
  </div>
  <?php
}