As challenge to myself (of learning some ruby), I have tried to add some code to the awesome cakeday plugin, that takes privacy and security into account whilst adhearing to existing coding conventions and my own ability thereof.
The code can be seen at https://github.com/DaVania/discourse-cakeday/commits/discourse-cakeday_with-age
I do hope 
it will be of use, and since this is my first use of Github as an contributor, I suspect that not everything is perfect, even though my efforts through many nights and months to make it just that. (Perfect)