使用DATE_ADD（）时SQL语法错误

so I am trying to return all appointments more than 24 hours ahead of time. I'm positive the error in the code is around the DATE_ADD stuff, so I know that the PHP variables are set correctly. I think I am just thinking about DATE_ADD wrong. I have also tried several variations of brackets with no luck. Just CURDATE() works. Thanks for any help!so I am trying to return all appointments more