Change icon with input_button helper

[agencetwogether]

Hi, I’m trying to make a card for input_button.

So this helper has no state on / off but returns the last time has been pressed.

So I would like to change icon for a duration when button is pressed (for eg 20s) and return to this original icon.

At the moment I do this :

type: custom:button-card
entity: input_button.gate_btn
name: Test
show_state: false
icon: >
  [[[
       var currentTimestamp = Math.floor(new Date().getTime() / 1000) 
       var lastTimestamp = Math.floor(new Date(states['input_button.gate_btn'].state).getTime() / 1000)
       var timeDiff = Math.floor((currentTimestamp - lastTimestamp) / 60)
       var timeDiffSecond = timeDiff * 60
        if (0 < timeDiffSecond < 20){
          return 'mdi:gate-open';
         }
         else{
           return 'mdi:gate'
         }
     ]]]

But not working... What's wrong ? Thanks for your help