Show_last_changed: true / false base on Idle

Configuration
1

I have got Custom UI 20171215 running working :slight_smile:

in customize i have

sensor.washing_machine_status:
  icon: mdi:washing-machine
  show_last_changed: true

  - platform: template
    sensors:
      washing_machine_status:
        value_template: '{{ states.input_select.washing_machine_status.state}}'
        friendly_name: 'Washing Machine Status'

  washing_machine_status:
    name: Washing Machine Status
    options:
      - Idle
      - Running
      - Finishing
      - Clean
    initial: Idle

could someone point down the path when it says “Idle”

to make the
show_last_changed: false

when not “Idle”
show_last_changed: true

thanks

If i go to he <> tool

Set entity to washing_machine_status

I can Change the State Attributes
“show_last_changed”: false

then click the SET STATE
and it work

Just need to how to Automate it