Is Zakat due on money invested in an Islamic bank for a period of 3 years annually, or at the end of the investment period by paying the full amount after knowing the outcome?

Zakat (definition) is obligatory on investment deposits in Islamic banks, on both the principal and the profits, every year, provided the conditions for Zakat are met, regardless of whether the deposit is long-term or short-term, and whether it has been withdrawn or not.