根据星期数和年份获取特定日期的日期

Question

I'm getting the year and the 'week-of-the-year' from the external source, which I'm not able to change. I'd like to get the date of Monday and Sunday of that concrete week. For now I've got the below code, but it seems pretty complicated.

<?php

// simulate the server data
$year = date('Y');
$week = 19;

$weekNow = (int) date('W');
$weekDiff = $week - $weekNow; // can be positive or negative
$daysDiff = $weekDiff * 30;

$dayInDesiredWeek = (int) date('N', strtotime($daysDiff . ' days'));  
if($dayInDesiredWeek !== 1) {
    $daysDiff += $daysDiff > 0 ? -($dayInDesiredWeek - 1) : $dayInDesiredWeek - 1;
}
$monday = date('Y-m-d', strtotime($daysDiff . ' days'));
$sunday = date('Y-m-d', strtotime($monday . '7 days'));

Is there any other (simpler) method I can use to get the same results? Thank you in advance.

Answer 1

So, the easiest solution I've seen so far, when I was reading the PHPDocs of DateTime Object .

So the steps are:

1. Create new DateTime() object
2. Run it's setISODate method with params: ($year, $weak, $offsetFromMonday)
3. then run format method and get the desired date

So, all together:

$monday = ($dt = new DateTime)->setISODate($year, $weak, 1)->format('Y-m-d');
$sunday = $dt->setISODate($year, $weak, 7)->format('Y-m-d');

Answer 2

 $dt = date("Y-m-d", strtotime("2017W01"));

use Carbon

 $dt = new Carbon($dt);

 var_dump($dt->startOfWeek());
 var_dump($dt->endOfWeek());