Thanks for advice, but as I tried and tested function "delayed shipping", I found it isn't what I need. On prestashop forum I found, it is for orders, where is some product not in stock, so customer can delayed order, but I need to add datepicker, so customer can choose day of his/her choose day, when order will be delivered, so If you have another option how to do it without need to buy paid module, it would be nice.