Strange behavior of Date Function

Question

I encountered with this question today on StackOverflow but didn't get answer.

My question is

echo date('Y-m-d',strtotime('2012-september-09')); // output - 2012-09-01

echo date('Y-m-d',strtotime('09-september-2012')); // output - 2012-09-09

Codepad

I am confused that why the first format don't produce correct answer. Any Help?

Answer 1

From the manual:

if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.

Answer 2

This is not behavior of the date function but of the strtotime. strtotime can handle only dates in specific formats listed on the Date Formats manual page. 09-september-2012 is in the dd ([ \t.-])* m ([ \t.-])* y format listed there, but 2012-september-09 does not match any of the supported formats.