strtotime february bug

Question

Okay, so I do understand that if I am running the strtotime function on a day that is the 29th or higher I will incur the February bug and get a result for March instead.

Also I get that if I set the date to Feb 1st, I can avoid the issue.

But here is the problem. I am rolling through the last 12 months of records to generate sales/billing numbers for tracking. How do I ask for all records in February when my loop looks like this?

setlocale( LC_MONETARY, 'en_US' );

$i = 0;
while( $i <= 11 ) {                 
  $select = "SELECT * FROM `my_table` " . 
            "WHERE YEAR( billing_date )  = '" . date( 'Y', strtotime( -$i . ' month' )) . "' " . 
            "  AND MONTH( billing_date ) = '" . date( 'm', strtotime( -$i . ' month' )) . "'";

  $result   = mysql_query( $select );
  $num_rows = mysql_num_rows( $result );

  $sales    = 16 * $num_rows;

  echo "<p align='center'>";
  echo   "Sales for " . date( 'M, Y', strtotime( '-' . $i . ' month' ) ) .
         "&nbsp" . money_format( '%i', $sales );
  echo "</p>";

  $i++;
}

How do I avoid the February bug? Would it be an if statement? What would that look like?

Answer 1

Here is a pure SQL solution (if I correctly understand the scenario):

SELECT 
    YEAR(billing_date) AS billing_year,  
    MONTH(billing_date) AS billing_month,
    16 * COUNT(*) AS sales /* Why x16?!!! */
FROM my_table
GROUP BY YEAR(billing_date), MONTH(billing_date)

This will calculate the sales directly in SQL, so in PHP you just need a display loop.

Answer 2

How do I ask for all records in February...

SELECT * FROM table WHERE MONTH(billing_date) = 2

Answer 3

February bug? It's not a bug. Normalizing dates is a (useful) feature! :-)

If you want the last day in February, ask for the 0th of March.

Answer 4

I don't know the "february bug", but you could try to use MySQL to subtract 1 month. Check

SELECT DATE_SUB(billing_date, INTERVAL 1 MONTH) FROM my_table

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