<?php include('includes/config/config.php'); error_reporting(E_ERROR | E_PARSE); $sql="select * from checkup_form where checkup_date='0000-00-00' "; $date1='2019-01-01'; // $date1=strtotime($date); //echo $sql; $result = mysqli_query($conn,$sql); echo mysqli_num_rows($result); while($row=mysqli_fetch_array($result)){ $date1=date('Y-m-d', strtotime($date1. ' + 1 day')); // echo "shuabh1". $date1; $up_query="update checkup_form set checkup_date='$date1' where checkup_id='".$row['checkup_id']."' "; echo $up_query; $result1 = @mysqli_query($conn,$up_query); } //echo "shuabh"; ?>