SAP HANA default value variable

Dear all.

I am using SAP HANA Studio Version: 2.2.14. I need to set a default value in a variable for a calculation view. For example, variable Z_DATE to have the last day of the current month as default value when the selection screen pops-up.

In BW it can be done using customer exit variables but no idea how to implement it in HANA.

Has anyone faced the same situation?

Thanks for the support,

Fran.