My not-quite-functioning CSV-modifying PHP file--not functioning even after class help. If anyone has ideas, do tell. I meanwhile have learned a faster way to do this. :)

csv_manipulate.php

<?php
ini_set("auto_detect_line_endings", true);

$fileName = 'cases.csv';

// set function for opening file
$file = fopen($fileName, "r+") or die("can't open file");

// recognize file as csv, get it to loop
while(($data = fgetcsv($file, 1000, ',')) !== FALSE) {
	// set the second column to old date
	$old_date = $data[1];
	
	// switch the order
	$new_date = explode('/', $old_date);
	$date = $new_date[2].'-'.$new_date[0].'-'.$new_date[1];
	
	// set the second column to new date
	$data[1] = $date;
	
	fputcsv($file, $data);
	
}



// close csv file
fclose($file);

?>