php获取指定日期之间的各个周和月的起止时间

<?php
class Datefmt{
?? function __construct() {}
? /**
?? * 根据指定日期获取所在周的起始时间和结束时间
?? */
? public function get_weekinfo_by_date($date) {
??? $idx = strftime("%u",strtotime($date));
??? $mon_idx = $idx - 1;
??? $sun_idx = $idx - 7;
??? return array(
????? 'week_start_day' => strftime('%Y-%m-%d',strtotime($date) - $mon_idx * 86400),
????? 'week_end_day' => strftime('%Y-%m-%d',strtotime($date) - $sun_idx * 86400),
????? );
? }
? /**
?? * 根据指定日期获取所在月的起始时间和结束时间
?? */
? public function get_monthinfo_by_date($date){
??? $ret = array();
??? $timestamp = strtotime($date);
??? $mdays = date('t',$timestamp);
??? return array(
????? 'month_start_day' => date('Y-m-1',$timestamp),
????? 'month_end_day' => date('Y-m-'.$mdays,$timestamp)
????? );
? }
? /**
?? * 获取指定日期之间的各个周
?? */
? public function get_weeks($sdate,$edate) {
??? $range_arr = array();
??? // 检查日期有效性
??? $this->check_date(array($sdate,$edate));
??? // 计算各个周的起始时间
??? do {
????? $weekinfo = $this->get_weekinfo_by_date($sdate);
????? $end_day = $weekinfo['week_end_day'];
?????? $start = $this->substr_date($weekinfo['week_start_day']);
????? $end = $this->substr_date($weekinfo['week_end_day']);
????? $range = "{$start} ~ {$end}";
????? $range_arr[] = $range;
?????? $sdate = date('Y-m-d',strtotime($sdate)+7*86400);
??? }while($end_day < $edate);
??? return $range_arr;
? }
? /**
? * 获取指定日期之间的各个月
? */
? public function get_months($sdate,$edate) {
??? $range_arr = array();
??? do {
????? $monthinfo = $this->get_monthinfo_by_date($sdate);
????? $end_day = $monthinfo['month_end_day'];
?????? $start = $this->substr_date($monthinfo['month_start_day']);
????? $end = $this->substr_date($monthinfo['month_end_day']);
????? $range = "{$start} ~ {$end}";
????? $range_arr[] = $range;
?????? $sdate = date('Y-m-d',strtotime($sdate.'+1 month'));
??? }while($end_day < $edate);
??? return $range_arr;
? }
? /**
?? * 截取日期中的月份和日
?? * @param string $date
?? * @return string $date
?? */
? public function substr_date($date) {
??? if ( ! $date) return FALSE;
??? return date('m-d',strtotime($date));
? }
? /**
? * 检查日期的有效性 YYYY-mm-dd
? * @param array $date_arr
? * @return boolean
? */
? public function check_date($date_arr) {
??? $invalid_date_arr = array();
??? foreach ($date_arr as $row) {
????? $timestamp = strtotime($row);
????? $standard = date('Y-m-d',$timestamp);
????? if ($standard != $row) $invalid_date_arr[] = $row;
??? }
??? if ( ! empty($invalid_date_arr)) {
????? die("invalid date -> ".print_r($invalid_date_arr,TRUE));
??? }
? }
}

<?php
??? require_once "Datefmt.class.php";
???? $datefmt = new Datefmt();
??? // 输出11月1日和30日之间的各周
??? var_dump($datefmt->get_weeks('2014-11-05','2014-11-29'));
??? /*成果为
??? array(4) {
????? [0]=>
????? string(13) "11-03 ~ 11-09"
????? [1]=>
????? string(13) "11-10 ~ 11-16"
????? [2]=>
????? string(13) "11-17 ~ 11-23"
????? [3]=>
????? string(13) "11-24 ~ 11-30"
??? }
??? */
??? // 输出2月1日和11月30日
??? var_dump($datefmt->get_months('2014-02-03','2014-11-29'));
??? /*成果为
??? array(10) {
????? [0]=>
????? string(13) "02-01 ~ 02-28"
????? [1]=>
????? string(13) "03-01 ~ 03-31"
????? [2]=>
????? string(13) "04-01 ~ 04-30"
????? [3]=>
????? string(13) "05-01 ~ 05-31"
????? [4]=>
????? string(13) "06-01 ~ 06-30"
????? [5]=>
????? string(13) "07-01 ~ 07-31"
????? [6]=>
????? string(13) "08-01 ~ 08-31"
????? [7]=>
????? string(13) "09-01 ~ 09-30"
????? [8]=>
????? string(13) "10-01 ~ 10-31"
????? [9]=>
????? string(13) "11-01 ~ 11-30"
??? }
??? */