Okay here's my problem. i'm using the uBlogsyPlugin and there i'm using the uBlogsyPost Documenttype for my events. 

In the frontend i'm using a flash xml driven calendar and in the xml i need the following structure:

<events year="" month="" date="">
<event></event>
<event></event>
<event></event>
</events>

So i will do the following:

I create a list called :

dynamic startEvent = Model.AncestorOrSelf(1).Descendants("uBlogsyPost");
form there it's collecting all the Posts.
In the next step i need the CreateDate as var compareDate and with the format ddMMyyyy.
Next step create a second dynamic list and return only nodes where CreateDate = compareDate