Description:
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An extremely common date format in the USA is middle endian, which is often expressed in one of two ways. Today's date (July 21, 2009) could be expressed as either of the following:

1. 07/21/2009
2. 07-21-2009

Currently, if the first version (1) is passed into strtotime(), it successfully parses the date. However, the second version (2) returns FALSE.

Reproduce code:
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<?php

var_dump(strtotime('07/21/2009')); // good
var_dump(strtotime('07-21-2009')); // bad

?>

Expected result:
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int(1248152400)
int(1248152400)

Actual result:
--------------
int(1248152400)
bool(false)