Simple date question

Hi Experts,

I do not know ABAP which explains my straight forward question.

I am coding in BI.

Based on an invoice date, I need to work-out the fiscal year.

If the month of the invoice date is >= 4, then the fiscal year, is the current year.

If the month of the invoice date is jan-march, then the fiscal year, it the current year-1.

Thank you.

PY