php常见小技巧，分割时间，直接上代码。

if (!empty($post['date'])) {
                // - 分割时间段
                $date = explode(",", $post['date']);
                $start = $date[0];
                $end  = $date[1];
                $param['start'] = $start;
                $param['end'] = $end;
                if (empty($sql)) {
                    $sql .= " create_time between '$start' and '$end'";
                } else {
                    $sql .= " and create_time between '$start' and '$end'";
                }
 }

 //获取当天开始到结束
 $time = date('Y-m-d');
 $start = date('Y-m-d').' 00:00:00';
$end = date('Y-m-d h:i:s',strtotime($time)+86399);

select from_unixtime(1464969600);  //2019-06-0400:00:00;

select str_to_date('2019-06-04', '%Y-%m-%d %H');   //'2019-06-0400:00:00;

MySQL日期格式化（format）取值范围。