Counting time while game not opened

So basically I want to develop a clicker game for android. Since there’s a feature that adds money over the time (like 5$/sec), the game should also add money while it’s closed. And I don’t really have an idea to do that in blueprints.
I mean i tried like get the last real time second while the game was opened and subtract it from the next time the game has opened.

Have a look here, similar thing, solved:

Thank you! :slight_smile: