Modify Windows Forms Control from another Project

Question

I have a Control lblDate in User Control MainScreen. I would like to modify it in a method in class Date, which is in another project

Answer 1

the propertie LabelDate is from the class of your userControl MainScreen, but you're not instatiating any userControl.. Which instance of MainScreen do you expect to modify then?

you should do

this.controlMainScreen.LabelDate = GameDate;

considering that you say in your comments, that you have

 FormMain.Designer.cs there is: this.controlMainScreen = new Adventurers_of_Wintercrest.UserControls.MainScreen();