Hello kdgeyser.
Your code seems to work indeed before the setVariable (for Nur_tem : you forgot to add the latest digit).
After deployment of version 7.8 I had plenty of Date issues even in Groovy scripts.
My suggestion is, right now, to try Groovy ans set a direct Java Date object (You still will have problems with forms).
Another workaroud is to use strings, so you can store the variable as a string and convert to a real date only when you need it (this could solve a lot of issues with forms).