Beginning and End of a certain week

[Anon]

Hi,

currently I have the problem, that I am looking for a function which returns the beginning an the End of a certain week of the year.

Say, I call the function getKWBeginEnd(35, 2001),
i want to get back list(20010827000000, 20010902000000).

Here is my solution:

function getKWBeginEnd($KW, $year)
{
$i = 0;

// The 400 are just to make sure we don't end up in an infinate loop.
//
while ( $i < 400 && $KW!=strftime("%V", mktime(1, 1, 1, 1, $i, $year)) ) {
$i++;
}

$begin = date("Ymd000000", mktime(1,1,1,1,$i, $year) );
$ende = date("Ymd000000", mktime(1,1,1,1,$i+6, $year) );

return array($begin, $ende);
}

Works fine so far, except for 1 date:
Week 52, in the year 2000.

I always get list(19991231000000, 20000106000000) as a return
which is definately wrong. Week 52 in the year 2000 is from
20001225 thru 20001231.

Who can help? I don't want to make this function overly complicated,
since it is called several throughout the site.

Thanks a lot,
Oliver

[[deleted]]

DId you search the forum?

[Anon]

Well, now i have searched the forum.

The search turned up a thread in which
you have already answered the question
to my problem.

This is the output of Rolf Script:
(http://www.phpbuilder.com/forum/read.php3?num=2&id=117992&thread=117950)

a day in week 52, year 2000 is : Sat 23 Dec 2000
base date: 2000-12-23

And sorry, but this is wrong.
Week 52 of the year 2000 started on December 25th, and goes through the 31st.

The algorithm I previously posted works fine for every week I tried, except for week52 in year 2000...

Any other ideas?

[[deleted]]

Actualy that code is correct, you just expect the week to start on a monday, where other people start it on sunday and even saturday.

Here's a simple routine I cooked up to check it.
You can adjust it a few days + or - to make your weeks start on the sunday or monday.

function getWeekStart($iWeek, &$iStamp)
{
$iDays = 1 + (($iWeek-1) * 7);
$iStamp = mktime(0, 0, 0, 1, $iDays, 2000);
};

for ($iWeek=1;$iWeek<=52;$iWeek++)
{
getWeekStart($iWeek, $iStamp);
echo $iWeek.' '.date('r', $iStamp)."<BR>\n";
};