dynamic time trigger not working. | Home Assistant | Page 1

For quite some time I've been using a sensor so that I could easily start up most of my automations based on it either being a weekday or weekend:

- sensor:
      - name: Room Wake up time
        device_class: timestamp
        state: >
          {% set weekday = today_at("07:20") %}
          {% set weekend = today_at("09:20") %}
          {{ iif(is_state('binary_sensor.workday_sensor', 'on'), weekday, weekend) }}

That could easily trigguer automations with :

at: sensor.room_wake_up_time
trigger: time

But now I wanted to be able to edit these values in a more convenient way through the dashboard (without having to edit the yaml file and reload HA)
So I've been playing with input.daytime for this purpose.
But I've honestly hit a roadblock.
I've tested triggering directly from the input_datetimes and it works. But this would required an if condition on every automation I have done so far in order to work with the binary option of weekday/weekend.
Am I missing something simple?

 - sensor:
      - name: Room Wake up time
        device_class: timestamp
        state: >
          {% set weekday = states('input_datetime.weekday_wake_up_time') %}
          {% set weekend = states('input_datetime.weekend_wake_up_time') %}
          {{ weekday if is_state('binary_sensor.workday_sensor', 'on') else weekend }}

input_datetime:
  weekday_wake_up_time:
    name: Weekday Wake Up Time
    has_date: false
    has_time: true
    initial: '07:20:00'  # Default time for weekdays
    icon: mdi:clock
  weekend_wake_up_time:
    name: Weekend Wake Up Time
    has_date: false
    has_time: true
    initial: '09:20:00'  # Default time for weekends
    icon: mdi:clock

#dynamic time trigger not working.