Dynamic mandatory variable initialization

Dear Experts,

I am beginner in design studio. I have a mandatory variable in BEx query where I need to populate the current calyear.month.

The scripting is required to be written in On Variable Initialization event and not in On Startup event as On Startup script doesn't remove popup while running the report.

However I have got the following code to pass a static value in a variable:

APPLICATION.setVariableValue("variable","201601");

But as per my requirement it should pass it dynamically using current date.

Can you please help me how should I pass a value to a dynamic mandatory variable using On Variable Initialization event.

Thanks and Regards,

Nitesh Kumar