php时间时间戳

/*
 *+ -------------------------------
 * 计算当天起始点和结束点时间戳 取出当天的数据
 *+ ------------------------------
 */

$year = date("Y");
$month = date("m");
$day = date("d");
$dayBegin = mktime(0,0,0,$month,$day,$year);//当天开始时间戳
$dayEnd = mktime(23,59,59,$month,$day,$year);//当天结束时间戳

$query = "SELECT * FROM `fanli_info` WHERE insert_time<$dayEnd AND insert_time>$dayBegin";