Calculate the next business day using the DMN table


I would like to know if it is possible to calculate the next business day using a DMN table and if has the ability to define rules using an Expression Language.



not sure if I understand fully what you’re asking.
You can use the structure condition builder in de DMN Decision Table editor to create basic expressions that can be combined into rules.
But you can also use custom / complex expressions. We use JUEL as expression language.
By surrounding the expression with ${} or #{} you indicate it’s a custom expression and your free to define what you want.
Both for input and output expressions.
We have some date related built in functions you can execute using custom JUEL expressions but not specific business date related functions. You will need to implement that yourself.
But the approach will remain the same.

Look here for more info on adding custom function delegates;

Here is a unit test demonstrating all of this.
Adding a custom function delegate to the engine configuration and executing it from a decision table.

Hope this helps.