Everything I have read about cream cheese frosting says 2 hrs. Keep in mind that includes the time you have it out to bring to room temperature yo make the frosting.
Ditto what Goreti said. If I want a cream cheese frosting taste, for a cake required to be on the counter for a few hours, I use Lorann Cream Cheese immulsion to impart the desired flavor. There is also a tried and true mock cream cheese frosting which uses white balsamic vinegar. https://www.cakecentral.com/recipe/61811/white-balsamic-american-buttercream
Sugar Sugar by SSmiley
