yyyy-mm-dd format with strtotime returning wrong result

Question

$originalDate1 = '2013-12-30';

echo $newDate = date("o-m-d", strtotime($originalDate1));

Displaying 2014 instead of 2013

Answer 1

The problem is the "o"

ISO-8601 year number. This has the same value as Y, except that if the ISO week number (W) belongs to the previous or next year, that year is used instead. (added in PHP 5.1.0)

You should use "Y" instead.

Answer 2

use Y-m-d instead of o-m-d

$originalDate1 = '2013-12-30';

echo $newDate = date("Y-m-d", strtotime($originalDate1)); // will output 2014-12-30