Thanks Erasio, you gave me some headway in how to do this.
I’ve added a simplified version of my graph in the image below and commented exactly how each step works. It’s actually pretty simple once you can get your own second counter to work and reset.
Use a delay as a loop. You have a part in your event graph where you enter into a delay node. This one goes into your “Set [float variable]” node which gets how much you want to increase and then the whole thing goes back into the delay node.
You could use the event tick and delta time. Multiply Delta Time with how much you want it to increase every second and set that every tick.