Calculating Week of the Month from a given date [ PHP ]

Let first understand the problem. In the following fig. we have 2 months calendar of March 2009 to April 2009.

Now 31^st March and 1^st April, both dates belong to 14^th Week of the Year, but in Week of the Month Calculation 31^st March will be 5^th Week of March and 1^st April will be 1^st Week of April. There is no such format is available for PHP date() function , so we will calculate the Week of the Month Programmatically.

Test Case: the program should return 1^st week of March and 2^nd Week of April respectively for given dates (dd/mm/yyyy) 07/03/2009 and 07/04/2009.

The Week of the Month can be determined by following equation

We can implement the equation in a PHP function as bellow

function getWeekOfTheMonth($dateTimestamp)
{
$d = date('j',$ dateTimestamp);
$w = date('w',$ dateTimestamp)+1; //add 1 because date returns value between 0 to 6
$dt= (floor($dayOfMonth % 7)!=0)? floor($dayOfMonth % 7) : 7;
$k = (($w-$dt) < style=""> $W= ceil(($dayOfMonth+$k)/7);
return $W ;
}

Now check the function with Test Cases.
For 07/03/2009 or 7^th March 2009:
$dateTimestamp = mktime(0,0,0,3,7,2009);
echo getWeekOfTheMonth($dateTimestamp) ." week of ".date(F,$dateTimestamp);
and the o/p is
1 week of March
For 07/04/2009 or 7^th April 2009
$dateTimestamp = mktime(0,0,0,4,7,2009);
echo getWeekOfTheMonth($dateTimestamp) ." week of ".date(F,$dateTimestamp);
and the o/p is
2 week of April

(c) Sourav Ray