There is a form with date input in the amount of 2 pieces (dtarrive, dtdepart) the format of these fields is dd-mm-yy because The database stores in the format yy-mm-dd must be converted to the format dd-mm-yy.
INSERT INTO tbooking(dtarrive, dtdepart, userid) VALUES (LOWER(DATE_FORMAT("20-12-2017",'%d-%m-%Y')), LOWER(DATE_FORMAT(22-12-2017,"%d-%m-%Y")),"777") In this form and in various variations, the date is put 0000-00-00. Field in DB type DATE.