Appium vs Xcode Simulator Differences

I have an app that I am testing that shows different behavior based on whether I test using the Simulator launched from Xcode vs Appium using my testing framework. Running the App from Xcode shows the correct date and displays the information correctly. If I run the same test through Appium the date is wrong and the date is not shown correctly? What could be casuing the different behavior in Simulators?