Description:
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When doing some math with dates and "ceiling" the result, I got a negative zero!
I don't understand how that can be, so I presume it's an error.

Test script:
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<?php

$dt = mktime (0, 0, 0, 5, 18, 2011);
$base = mktime (16, 16, 0, 5, 18, 2011);

echo 'dt: ', date ('Y-m-d', $dt), '<br />';
echo 'base: ', date ('Y-m-d', $base), '<br />';

echo '<br />';
echo 'dt - base: <strong>', ceil (($dt - $base) / 86400), '</strong>';

?>
<br /><br />
It outputs "-0" on PHP 5.3.6, under Windows XP 32 bits

Expected result:
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The bolded text should be "0" (zero)

Actual result:
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The bolded text is "-0" (negative zero)