How do I? Create a timer / countdown for working from home triggered by a motion sensor

Configuration
1

Hello,
I’m looking to you good folk to give me some inspiration / help on how to do the following:

I am looking to start a 7.5 hours countdown once a PIR sensor sees motion after 5 AM (for example). At 7 hours 15 minutes, I would like to warn me my working day is about to finish and then at 7.5 hours send another message.

I can use the - service: notify.notify to send messages to my phone etc but it’s the timer / countdown I’m struggling with.
Any help is gratefully received!

2

I would create 2 timers in helpers one for 7h 15m one for 7h 30m Then use triggers, something like this?

description: ""
mode: single
trigger:
  - platform: state
    entity_id:
      - binary_sensor.some_motion_sensor
    from: "off"
    to: "on"
    id: motion-started
  - platform: event
    event_type: timer.finished
    event_data:
      entity_id: timer.first_timer
    id: Nearly-end-of-day
  - platform: event
    event_type: timer.finished
    event_data:
      entity_id: timer.second_timer
    id: end-of-day
condition: []
action:
  - choose:
      - conditions:
          - condition: trigger
            id: motion-started
        sequence:
          - service: timer.start
            data: {}
            target:
              entity_id: timer.first_timer
      - conditions:
          - condition: trigger
            id: Nearly-end-of-day
        sequence:
          - service: notify.mobile_app_some_phone
            data:
              message: Nearly end of day
      - conditions:
          - condition: trigger
            id: end-of-day
        sequence:
          - service: notify.mobile_app_some_phone
            data:
              message: Stop work

Probably not bang on, but it will get you going hopefully.

3

Thanks so much - worked first time!