brightness helper to slowly (linear) dim the lights from 17:00 - 20:00 and then inverted exponential until 23:00. Use in automations to call light.turn_on in Home Assistant.

configuration.yaml

- platform: template
      sensors: 
          lightbrightness:
            friendly_name: 'light brightness - helper'
            unit_of_measurement: '%'
            value_template: >
             {% if now().hour > 16 and now().hour < 23 %}
             {% set timer = now().minute+((now().hour-17)*60) %}
             {% set const = 1.01452 %}
             {% set hourdivider = ((now().hour/20)-0.45)|round(0) %}
             {{ 255-((45/180)*timer)+(hourdivider*(-(const**timer)+13.4)) }}
             {% elif now().hour < 7 or now().hour == 23 %}
             3
             {% else %}
             255
             {% endif %}