Derivative rule not working on time dimension

Hi, I’m trying to run a derivative rule source - final at time dimension so that I can copy the loaded amount across 12 month.

In the source I have a Period column with the year. 

My idea is to bypass the year in one to one mapping and create 12 months using the derivative rule. 

Something like this 

The issue I’m facing is that the derivative is duplicating the rows but not changing the time, however I test for other dimensions and it’s working.

Has the time dimension any restriction on derivative rules?

Thanks