Convert week to fist day of week

[Yamakazi]

Hello,

With the function -->date("w", $date)<-- you can get the week of the date that's entered. Know i have to do it the opposit way. I've got a week and i have to know what dates are in that week. Or just the first day would be fine. (with the week starting on a monday, Belgium kinda thing) Can some one get me started with something like that?

TIA

[nnichols]

-->date("w", $date)<-- will actually give you the day of the week not the week of the year, you need -->date("W", $date)<--.

Do you need to get the start of the week based on a week number or a date?

[Yamakazi]

I give a week number and it has to return the first day of the week in date form.

Example

Input week 3
Output 20030113

THX

[nnichols]

I can't think of a simple way of doing this with any of php's native date functions. I think you will have to do something like this -

// pseudo code
function get_week_start($week_no, $year) {
// use $week_no to build an approx date
$month = floor($week_no / 4);

$date = strtotime("1st $month $year");

// then we need to loop adding to the date until we have day=1 (monday) and week_no=$week_no

while (date('W', $date) != $week_no || date('w', $date) != 1) {
// have some code here to increment the $date by 1
}

return $date;
}

There must be a simpler way of doing it but I don't know it.

[Weedpacket]

Indeed, another solution can be found here.
Ain't search facilities grand?

[nnichols]

cheers Weedpacket 😉 - beats the hell out of my version (though it does work)