Automation Help - All Day Calendar Event trigger Fails To Execute Automation

Configuration
1

Hi, can I get some help please - I have created an automation that should turn on an input_boolean 1 hour before an all day event starts however the trigger never runs. If I manually run the automation when the event is in the calendar the input boolean is switched on:

alias: School - Holidays Day On
description: ""
trigger:
  - platform: calendar
    event: start
    entity_id: calendar.family
    offset: "-01:00:00"
condition:
  - "{{ trigger.calendar_event.all_day }}"
  - "{{ 'School Holiday' in trigger.calendar_event.summary }}"
action:
  - service: input_boolean.turn_on
    data: {}
    target:
      entity_id: input_boolean.school_holidays_day
mode: single

I am running the latest version of HA.
The calendar is a family ICloud calendar

2

If you sort this out, let me know.

I’m looking to turn on a boolean when a calendar day event exists as well. Both for school holidays and standard holidays.

Thanks!