I am making a birthday cake it will be covered with fondant, what will keep longer butter ream or cream cheese filling, i need a filling that will last more than a week?

Buttercream for sure!

Thank you, new to this lol x

Cream cheese anything, (made with real cream cheese), is VERY perishable and cannot be out of a refrigerator for more than 2 hours or it becomes potentially unsafe.  

Ok thanks for advice will definitely remember that for future, but what about the ready made cream cheese filling you buy in supermarkets ? Confused !. 

If you are talking about cream cheese pastry filling, the manufacturer says it can be stored at room temperature in a sealed container for up to two weeks.  Since this is flavored cream cheese and not actual cream cheese, no refrigeration is needed.  The pastry filling I use is http://www.countrykitchensa.com/shop/ingredients-icing-colors-flavors/pastry-filling-cream-cheese/46/587/798/619081/.  I believe the brand to be Henry's.  The filling can also be added to buttercream and does not break the buttercream down (1/2 cup pastry filling to 6 cups of buttercream).

If you are talking about cream cheese pastry filling, the manufacturer says it can be stored at room temperature in a sealed container for up to two weeks.  Since this is flavored cream cheese and not actual cream cheese, no refrigeration is needed.  The pastry filling I use is http://www.countrykitchensa.com/shop/ingredients-icing-colors-flavors/pastry-filling-cream-cheese/46/587/798/619081/.  I believe the brand to be Henry's.  The filling can also be added to buttercream and does not break the buttercream down (1/2 cup pastry filling to 6 cups of buttercream).

If you are talking about cream cheese pastry filling, the manufacturer says it can be stored at room temperature in a sealed container for up to two weeks.  Since this is flavored cream cheese and not actual cream cheese, no refrigeration is needed.  The pastry filling I use is http://www.countrykitchensa.com/shop/ingredients-icing-colors-flavors/pastry-filling-cream-cheese/46/587/798/619081/.  I believe the brand to be Henry's.  The filling can also be added to buttercream and does not break the buttercream down (1/2 cup pastry filling to 6 cups of buttercream).