strtotime woes

Hello all. Long time no see! Anyway, I'm having an issue with strtotime(). Why do the following return valid timestamps? <?php echo strtotime ('a').': '.date ("m/d/Y", strtotime ('a'))."<br/>"; echo strtotime ('a,a').': '.date ("m/d/Y", strtotime ('a,a'))."<br/>"; echo strtotime ('a,a,a').': '.date ("m/d/Y", strtotime ('a,a,a'))."<br/>"; ?> These result in today's date: 1273049449: 05/05/2010 1273049449: 05/05/2010 1273049449: 05/05/2010 Each time the page is reloaded, the seconds jump up... but still today's date. Why is this? I can repeat the same results by changing the 'a' to any other single letter: "g" or "h,k" or "r,s,t" or whatever - all the same result. Thanks, ~Philip