<?php
$now_time = time();$date=date("Y-m-d",$now_time);function get_date($date,$t='d',$n=0){    if($t=='d'){       $firstday = date('Y-m-d 00:00:00',strtotime("$n day"));       $lastday = date("Y-m-d 23:59:59",strtotime("$n day"));    }elseif($t=='w'){       if($n!=0){$date = date('Y-m-d',strtotime("$n week"));}       $lastday = date("Y-m-d 00:00:00",strtotime("$date Sunday"));       $firstday = date("Y-m-d 23:59:59",strtotime("$lastday -6 days"));    }elseif($t=='m'){       if($n!=0){$date = date('Y-m-d',strtotime("$n months"));}       $firstday = date("Y-m-01 00:00:00",strtotime($date));       $lastday = date("Y-m-d 23:59:59",strtotime("$firstday +1 month -1 day"));     }    return array($firstday,$lastday);}$day1   = get_date($date,'d');$day2   = get_date($date,'d',-1);$week1 = get_date($date,'w');$week2 = get_date($date,'w',-1);$month1 = get_date($date,'m');$month2 = get_date($date,'m',-1);echo '<pre>';print_r($day1);//今天print_r($day2);//昨天print_r($week1);//这周print_r($week2);//上周print_r($month1);//这月print_r($month2);//上月echo '</pre>';