Problem with dates loading a xml

I’m generating a xml file with php, but, some dates display wrong.
I check the xml and these are ok!!
I don’t know why is that, can someone help me!!
That happen to me always when the xml pass from a month to another month.

Thanks for your help!!

you have 2010,09,30
it should be 2010,9,30
please skip extra zeros at the beginning.