使用PHP查找工作日，工作日和工作日的日期

Question

I have a day of the week number 'N' (1 for Monday through 7 Saturday) and a week 'W' and a year 'Y'.

How can i find the date?

Day of the week: 4 Week: 35 Year: 2014

Should output: 2014-08-28 (Thursday)

I have tried using strotime() without any luck. I cannot seem to find a way to specify the week and year, together with the weekday number.

Answer 1

Just did my own solution. Here is how you could do it.

function getDayDate($day, $week, $year) {
  $day -= 1;

  $dto = new DateTime();
  $dto->setISODate($year, $week);
  $dto->format('Y-m-d') . ' 00:00:00'; // start of the week date
  $dto->modify('+'.$day.' days'); // add the days
  $result = $dto->format('Y-m-d') . ' 23:59:59';
  return $result;
}

$getdate = getDayDate(4, 35, 2014);

echo $getdate;

Answer 2

You can use DateTime 's setISODate() method for exactly this purpose. Your solution is almost right, but I don't understand why you're not supplying the weekday argument right from the start.

function get_date($weekday, $week, $year) {
    return (new DateTime())->setISODate($year, $week, $weekday)->format('Y-m-d');
}

var_dump(get_date(4, 35, 2014));