One Sensor sensor should be on when it’s today and one sensor should be on when it’s tommorow (24h offeset)
I tried this one
{% if is_state_attr('calendar.mygooglecalendar', 'message', "Schulfrei") %}
true
{% else %}
false
{% endif %}
But it shows that the event is active at the moment, but there is no appointment today?
If your calendar can reasonably be expected to have overlapping/coincident events you should not base your sensor on the state of the calendar entity, you will need to use a trigger-based template binary sensor and the calendar.get_events service.
This means i have to put this whole template into the configuration yaml to get the sensor?
Looks complicated, it was so easy for my caldav calender
- platform: caldav
url: url
username: "user"
password: "pass"
custom_calendars:
- name: "Schulfrei"
calendar: "name"
search: "Schulfrei"
No.
it means you create a template sensor -
template:
- trigger:
- platform: time_pattern
minutes: "/5"
action:
- service: calendar.get_events
data:
duration:
hours: 48
target:
entity_id: calendar.googlecalendar
response_variable: agenda
binary_sensor:
- name: Event Today
state: >-
# your code here
Thanks I insert this in the configuration.yaml:
template:
- trigger:
- platform: time
at: "00:01:00"
action:
- service: calendar.get_events
data:
start_date_time: "{{ today_at() }}"
end_date_time: "{{ today_at('23:59:00') }}"
target:
entity_id: calendar.xyz
response_variable: agenda
binary_sensor:
- name: Schulfrei xyz Heute
state: |-
{% set search_term = "Schulfrei" %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | list | count > 0 }}
- trigger:
- platform: time
at: "00:01:00"
action:
- service: calendar.get_events
data:
start_date_time: "{{ today_at() + timedelta(days= 1)}}"
end_date_time: "{{ today_at('23:59:00') + timedelta(days= 1) }}"
target:
entity_id: calendar.xyz
response_variable: agenda
binary_sensor:
- name: Schulfrei xyz Morgen
state: |-
{% set search_term = "Schulfrei" %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | list | count > 0 }}
OK - but, if the second calendar is the same calendar - you don’t need to use a second trigger and second service call.
template:
- trigger:
- platform: time
at: "00:01:00"
action:
- service: calendar.get_events
data:
start_date_time: "{{ today_at() }}"
end_date_time: "{{ today_at('23:59:00') }}"
target:
entity_id: calendar.xyz
response_variable: agenda
binary_sensor:
- name: Schulfrei xyz Heute
state: |-
{% set search_term = "Schulfrei" %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | list | count > 0 }}
- name: Schulfrei xyz Morgen
state: |-
{% set search_term = "Schulfrei" %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | list | count > 0 }}
Would be nice beeing able to shorten the code, the problem is, that with your solution both sensor would give the same state.
I need different Start/end Times.
I’m working on that now 
OK here it is:
template:
- trigger:
- platform: time
at: "00:01:00"
action:
- service: calendar.get_events
data:
start_date_time: "{{ today_at() }}"
duration:
hours: 50
target:
entity_id: calendar.xyz
response_variable: agenda
binary_sensor:
- name: Schulfrei xyz Heute
state: |-
{% set search_term = "Schulfrei" %}
{% set d = today_at()|as_timestamp|timestamp_custom("%Y-%m-%d") %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | selectattr('start','eq',d) | list | count > 0 }}
- name: Schulfrei xyz Morgen
state: |-
{% set search_term = "Schulfrei" %}
{% set d = (today_at() + timedelta(days=1))|as_timestamp|timestamp_custom("%Y-%m-%d") %}
{{ agenda['calendar.xyz'].events
| selectattr('summary', 'search', search_term) | selectattr('start','eq',d) | list | count > 0 }}
Is it not necessary insert times in today_at() ?
No, it defaults to midnight ( “00:00:00” ) if you leave it empty.
And midnight → midnight of the same day is not zero?
And the duration is necessary now?
Duration just makes it easier to say I want events within this many hours of the start time, rather than having to code another template for the end time.
So we are saying start at 00:00:00 - using today_at() is doing the same as
now().replace(hour=0,minute=0,second=0)
and fetch events within 50 hours of the start time.
okay, then the duration should be 24 hours?
No, because you want to detect events tomorrow too - since you are doing a sensor of an event that is today and a sensor for an event tomorrow.
but the duration of today is 24h and the duration of tommorow is 24 h 
Good point, that’s what late night coding does for you.
It doesn’t really matter with the code I posted though, because we are matching the date of today and the date of tomorrow, there could be 7 days worth of events, it will still only match today and tomorrow.