In M, the DateTime.LocalNow() function returns the current system date and time at the time the function is called – which means that you could call it multiple times in the same query and get different results. There’s also the DateTime.FixedLocalNow() function which also returns the system date and time; the difference between the two is, as the documentation says:
With Dynamics Nav 2016 you now have the ability to make events. While this makes creating add-ons much easier and minimize the impact on existing code. It might become harder to debug though. How do you know what functions are subscribed to your event? What order do these responses happen?