PHP Week converted to date (last day) dates ("O-w") to y-m-d date--Post code

O-w Week converted to the last day of the normal date week public    function Weektodate ($oW) {        $oW = explode ("-", $oW);    Split o-w Zhou Weihin and weeks        $year = $oW [0];//year        $week = $oW [1];//week number        $weekYearBegin = Date ("W", Strtotime ($year. ") -01-01 "));   The beginning of January 1 is the day of the week, 0-6,0 is Sunday, 1-6 is Monday to Saturday        $WYearBegin = Date ("W", Strtotime ($year. " -01-01 "));  The beginning of January 1 is the first week of the year, which may be the start of the month: 01, or the last week of the past:        if ($WYearBegin = = "") {    //The first week of the year            $days = (7-$weekYearBegin)% 7 + (int) ($week-$WYearBegin) *7;  Need to calculate the last day of the week (Sunday), distance from the beginning of January 1 How many days        }else{  //last week of previous year            $days = (7-$weekYearBegin)%7 + (int) ($week) *7;  The last day of the week to be calculated (Sunday), the number of days from the beginning of January 1        }        $lastDayOfW = Date ("y-m-d", Strtotime ($year. " -01-01 + ". $days." Days "));  Because it is the last day (Sunday), it must fall in the year ($year), or the next year, and not fall in the previous year with $year +n days        return $lastDayOfW;    }

The above is implemented for the entire code, and returns the date ("y-m-d") of the Last Day (Sunday) of the week of the date ("O-w").

PHP Week converted to date (last day) dates ("O-w") to y-m-d date--Post code