Calculate sleep time

[Johann_Edelmuller (Johann)]

I would like to use these two sensors to show the mean time in one sensor, how long until the alarm (sleep time)

How can I best do that?
Can someone help me?

[pnbruckner (Phil)]

Do you mean you want another sensor to show the amount of time between the current time and the next alarm time? If so, then maybe try this:

sensor:
- platform: template
  sensors:
    time_to_wakeup:
      value_template: >
        {% set t = states('sensor.time').split(':') %}
        {% set t = t[0]|int*60 + t[1]|int %}
        {% set a = states('sensor.wakeup_alarm_time').split(':') %}
        {% set a = a[0]|int*60 + a[1]|int %}
        {% if a < t %}
          {% set a = a + 24*60 %}
        {% endif %}
        {{ ((a - t)*60)|timestamp_custom('%H:%M', false) }}

[Johann_Edelmuller (Johann)]

what can I say you are great! Thank you very much and a happy new year!