Find second and fourth saturday's of the month

I'm not sure why yours won't work, but try this, it worked for me:

echo '<br/>june 2nd sat '.date('d', strtotime('second sat of june 2013'));
echo '<br/>june 4th sat '.date('d', strtotime('fourth sat of june 2013'));

It's based on the "first sat of July 2008" example in the PHP manual page

I don't know why it is causing this error howver I've found solution how to get correct answers

echo date('d',strtotime('+1 week sat may 2013')).'<BR>';
echo date('d',strtotime('+3 week sat may 2013')).'<BR>';
echo date('d',strtotime('+1 week sat june 2013')).'<BR>';
echo date('d',strtotime('+3 week sat june 2013')).'<BR>';

This solution works fine and shows proper results.

Output:

11
25
08
22