Compute Bank Holidays

[cmdr_bond]

Hi,

I was trying to make a function which gives a list of the bank holidays in a given year. How would I go about finding the date of the last Thursday in November, for example (Thanksgiving)?
I thought of using the strtotime function, but it doesnt seem to like my entry:

date('m-d-Y',strtotime('last thursday in November'));

Thanks

//Easy ones
January 1 //  New Year's Day - always the same
July 4 // Independence Day - always the same
November 11 // Veterans Day  - same
December 25 // Christmas Day  - same

//Not too hard
January 20 // Inauguration -  every fourth year, following Presidential election 

//Harder ones
January 15 // Martin Luther King, Jr.'s Birthday - Third Monday of January
February 19 // Washington's Birthday - Third Monday in February
May 28 //  Memorial Day - Last Monday in May
September 3 // Labor Day - First Monday in September
October 8 // Columbus Day - Second Monday in October
November 22 // Thanksgiving Day - Fourth Thursday in November

[Scriptmaker]

<?php

date_default_timezone_set('UTC');

function GetDay($month,$year,$number,$dayofweek) {

//initialize some variables
$count=0;
$holiday=0;

for ( $d = 1; $d <= 31; $d++) {

$day = date("l", mktime(0, 0, 0, $month, $d, $year));
if ($day == $dayofweek) {
$count++;
if ($count == $number) {$holiday = $d;}
}

}
return $holiday;
}

$mlk = GetDay(1,2007,3,"Monday");
echo "MLK Day is on: 1/".$mlk."/2007<br />";

$wash = GetDay(2,2007,3,"Monday");
echo "Washington's Birthday is on: 2/".$wash."/2007<br />";
?>

That should take care of the last ones, let me know if you need me to explain anything.

[bradgrafelman]

Interestingly enough, this seems to have been a common application in the past; have you seen this user-contributed note?

[NogDog]

Just felt like putzing around with this a bit, so here's what I came up with (including a bunch of defensive coding):

/*
* int nthDay(int $month, str $day, int $n[, int $year])
* returns UNIX timestamp or FALSE on failure
* $day is 'monday', 'tuesday', etc. (case-insensitive)
* $year defaults to current year
*/
function nthDay($month, $day, $n, $year = 0)
{
   $month = (int) $month;
   $day = strtolower($day);
   $year = ($year) ? (int) $year : (int) date('Y');
   $n = (int) $n;
   if(!checkdate($month, 1, $year))
   {
      user_error("nthDay(): invalid month and/or year");
      return(FALSE);
   }
   if($n < 1 or $n > 4)
   {
      user_error("nthDay(): invalid value '$n' for 3rd parameter");
      return(FALSE);
   }
   if(!in_array($day, array('monday', 'tuesday', 'wednesday', 'thursday',
         'friday', 'saturday', 'sunday')))
   {
      user_error("nthDay(): invalid day '$day'");
      return(FALSE);
   }
   return strtotime("+$n weeks", strtotime("Last $day", 
          mktime(0, 0, 0, $month, 1, $year)));
}
// sample usage:
printf("Thanksgiving this year: %s", date('Y-m-d', nthDay(11, 'Thursday', 4)));