I don’t know any tutorial about this and don’t have unreal here right now but let me try to explain it a bit better.
You don’t want the clean time but just a value with a min and max border right?
Well instead of this “get input key time down” you can each tick if your branch is true (and by tick I mean each time event tick is called which is each frame) add a value to that variable. Don’t set it new. Just get that variable and add a value.
And this value should be delta time (which is the float output of event tick and represents the time since the last tick) multiplied by the value you want your variable increased by each second.
Before you use the variable use the node “clamp”. It takes a min and max and will only output banks in between or either of those extreme values.