loop of reset

I need to repeatedly reset (or press F8) a node every other 15 min or even better when the entire workflow ends. How can I do this? For example, I have a "List Files" node, and I would like to reset this node every 15min to rescan the list of files every other 15 min as the folder changes the number of files to be listed in this node. I could not use any loop as this node does not have an input.

Looking forward to your response.

 

Every node has a hidden flow variable input at the top left corner that gets visible when you create a connection to it. Even if you don't use any flow variables you can use these ports to define a dependency on predecessing nodes.