How to change bean's block view mode programmatically?
You can use hook_entity_view_mode_alter()

function MYMODULE_entity_view_mode_alter(&amp;$view_mode, $context) {  
    if ($timevalue1 == $value1) {  
      $view_mode = 'view_mode1';  
    } elseif {  
      .......  
    }  
}