Would this date calculation be possible?

[roach]

Hello,

I have a date in the format of year-month-day (2002-1-1).

What I am trying to do is find the week in which this day occurred.

So, if i had 2002-1-1 it would equal:

Sunday December 29, 2002 till Saturday January 4, 2003.

Im not really worried about the day conversion, so if it was equal

to 2002-12-29 through 2003-1-4 that would work good also.

Is this even possible? Thanks for any help/tips =)

-r

[gtibok]

hi
one easy way is to collect the days in the "z" format - z - day of the year; i.e. "0" to "365"
$z = date("z");
$w = ceil($z/7);

OR convert d to z and than z to w
function week_number(){
$date = date ('Y-m-d');
$exp = explode ("-" , "$date"); //this will create an array
//extracting year, month and day from the array
$Y = $exp[0];
$m = $exp[1];
$d = $exp[2];
// now the hard part;
$year_29 = array ("1996", "2000", "2004", "2008", "2012"); //add here all the 29 february years it may count!

// DO NOT edit under this line
if (!in_array($Y, $year_29)){
if($m == 1){ $z = $d; }
if($m == 2){ $z = $d + 31; }
if($m == 3){ $z = $d + 59; }
if($m == 4){ $z = $d + 90; }
if($m == 5){ $z = $d + 120; }
if($m == 6){ $z = $d + 151; }
if($m == 7){ $z = $d + 181; }
if($m == 8){ $z = $d + 212; }
if($m == 9){ $z = $d + 243; }
if($m == 10){ $z = $d + 273; }
if($m == 11){ $z = $d + 304; }
if($m == 12){ $z = $d + 334; }
}
else {
if($m == 1){ $z = $d; }
if($m == 2){ $z = $d + 31; }
if($m == 3){ $z = $d + 60; }
if($m == 4){ $z = $d + 91; }
if($m == 5){ $z = $d + 121; }
if($m == 6){ $z = $d + 152; }
if($m == 7){ $z = $d + 182; }
if($m == 8){ $z = $d + 213; }
if($m == 9){ $z = $d + 244; }
if($m == 10){ $z = $d + 274; }
if($m == 11){ $z = $d + 305; }
if($m == 12){ $z = $d + 335; }
}
$w = ceil($z/7);
return $w;
}

//call the function
echo week_number();
$week = week_number();
----- Good Luck

[Weedpacket]

...or you could just use date('w') to find out what day of the week the given date is, subtract that number of days to find the Sunday of that week, then add 6 days to that to find the final Saturday...

$date=mktime(make a timestamp)
$day_of_week=date('w',$date);
$sunday = $date-$day_of_week*86400;
$saturday = $sunday+6*86400;

Then use date() to convert $sunday and $saturday into the appropriate format.

Edit. That's the lazy way of doing it and it doesn't account for daylight saving.
$day, $month, $year are the day, month and year of the date we want to find the weekends of:

$day_of_week = date('w',mktime(12,0,0,$month, $day, $year));
$sunday=mktime(12,0,0,$month, $day-$day_of_week, $year);
$saturday=mktime(12,0,0,$month, $day-$day_of_week+6, $year);

And yes, PHP will know what to do with negative dates.

[gtibok]

hi Weedpacket!
Myabe I am wrong , but I think you answered to another question, please corect me and accept my appologies if I'm wrong

[Weedpacket]

Well, that's for roach to answer, but the code I wrote will supply timestamps for the Sunday and Saturday that form the ends of the week containing the supplied day; e.g., if the date given is 1 January 2003, $sunday will refer to 29 December 2002 and $saturday to 4 January 2003, as described in roach's post.

What does your code return? I won't comment on the style, but wouldn't a suitable use of date('W') simplify it greatly (assuming PHP>=4.1)?

[roach]

Thanks for the help guys.

Weedpacket,
I already had the value of week-day so that made yours even easier.. 4 lines of code =)

$sat=mktime(12,0,0,$m, $d-$wday+6, $y);
$sun=mktime(12,0,0,$m, $d-$wday, $y);
$saturday=date("l F j, Y", $sat);
$sunday=date("l F j, Y", $sun);

THANKS!

-r