DMN age calculation


I would like to make a decision based on the age of a person in the DMN. As input I can only enter the date of birth. How can I use the Literal Expression to calculate the age and check in the DMN whether the person is older or younger than 18?

Hi @fabiannaether,

there is a nice playground to build and test feel functions: Try out and learn DMN FEEL - FEEL Playground

My result is:

substring after(
               substring before(
                                     years and months duration(

You can find the feel functions and expressions here: What is FEEL? | Camunda Platform 8 Docs

Hope this helps, Ingo

Addition: input is

  "birthday": "1969-05-31"

output is


Hello @Ingo_Richtsmeier,
thank you for the message. If I create this as a Decision Table and then try to simulate this in the DMN Simulator, I get the following error message:

If I put in a hardcoded date instead of today(), then it works. Have I made a mistake in the DMN file? Attached is the file.
AgeDMN.dmn (2.9 KB)

You could simplify the FEEL expression a bit by using the years property of the duration.

years and months duration(date(birthday), today()).years

It is an example from Temporal Samples | FEEL-Scala

Hello @Philipp_Ossler,

thank you for the message. Unfortunately, the same error appears. Why is the today() function not recognised?


It seems that the DMN simulator is outdated. :sweat_smile:

cc: @Ingo_Richtsmeier