### Clue: I act by instinct towards the west's festival (6)
### Answer: DIWALI 
 ### Explanation: Definition: festival
 **Reversal of**(towards the west, in an across clue) [ I + LAW(an act passed by government) + ID(in psychoanalysis, that part of the unconscious mind that's the source of primitive instinct).
Answer: Like its other name, "Divali", a contraction of "Deepavali", the Hindu "festival of lights". For a while, I was trying to fit "Divali" in.