Display relative time on button

Configuration Frontend
1

I spend hours to solve this problem, but without success. I have timestamp sensor defined like below:

timer:
  timmeon_timer:
    duration: "00:01:00"

sensor:
  - platform: template
    sensors:
      timmeon_remaining:
        value_template: "{{ state_attr('timer.timmeon_timer', 'finishes_at') }}"
        device_class: timestamp

Additionally I have button defined like below:

type: button
entity: sensor.timmeon_remaining
show_state: true
tap_action:
  action: call-service
  service: script.timmeon_start
hold_action:
  action: call-service
  service: script.timmeon_stop

Problem is that on ‘entities’ card it displays relative time, but on button it just displays static date/time value. Please see below screenshot.
Bez tytułu
How can I display relative time also on button?