If I create a LeaveDate dateTime property in a module and create a dateTime object in a method:
Var LeaveDate As New DateTime(Val(year(ArrayElement).Text),month(ArrayElement).listIndex,Val(day(ArrayElement).Text),Val(hr(ArrayElement).Text) + (12*AmPm(ArrayElement).listIndex),Val(minutes(ArrayElement).Text))
why would LeaveDate be nil when I attempt to use it in another method?
That’s because LeaveDate is defined in a method. So it only exists while this method runs – see Scope in the documentation.
In order to preserve it, the property must be saved in a place where it lives beyond the runtime of the method, like a module, window or class property.
I think I mentioned the property is stored in a module which should be global if I’m correct.
Because you’re creating a local variable, which will be destroyed at the end of the method, rather than using your global variable. Change that to
LeaveDate = New ....
Var in your code means a new private method property is created. If you have another property of the same name somewhere else, don’t use Var but address this property directly.
Tim was faster. 
You did but you said you create it in a method. When the method returns, your locally declared variables (which live on the stack), go out of scope and are destroyed.
Some mornings I really need someone to watch over me. You was first to answer Ulrich. Thanks for the quick response.
Tim, does the App treat properties any different then a module?
The only real difference is you have to namespace app variables (app.LeaveDate) where in a module you can choose to do so or not.