Have timestamp (varying day to day), want to use it!

Configuration
#1

What I want to achieve:
I have a terrarium full of plants that normally reside in tropical or sub-tropical areas. I thought it would be pretty cool to give them a daylight cycle that is the same as some place close to the equator. So I want the lights to turn on when the sun goes up at some specified place and turn off when the sun sets.

What I have done:
I found an open API that gives me sunrise and sunset times as JSON (for some random spot in Africa), here: https://api.sunrise-sunset.org/json?lat=9.757452&lng=16.415384
I use the RESTful integration to “extract” the variables sunrise and sunset respectively to two entities that I call “sensor.sun_tropic_sunrise” and “sensor.sun_tropic_sunset”.

This is where I am lost. I have tried a couple of different ways I found here on the forum, one was using a template for the “action” that had an if-else-clause checking if the current time is before or after sunset and sunrise, setting switch off or on. That partly worked; I got it to print the right switch state but it never triggered. I can’t remember what I set the trigger to… I believe I even tried setting trigger to template sensor.sun_tropic_sunrise == True and still nothing.

I’ve also tried this:

  trigger:
  - platform: time
    at: "{{ as_datetime(states('sensor.sun_tropic_sunset')[:19]) }}"

It doesn’t set it off either.

Any suggestions as to what I should try next?

#2

What does the following return in Developer Tools → Template editor

{{ states('sensor.sun_tropic_sunset') }}
{{ as_datetime(states('sensor.sun_tropic_sunset') }}
{{ as_datetime(states('sensor.sun_tropic_sunset')[:19]) }}

Can you also share the configuration of your rest sensors.

#3

Set the device_class of both sensors to timestamp and ensure the reported date and time are in ISO format. This allows them to be referenced directly by a Time Trigger.

rest:
  - scan_interval: 3600
    resource: https://api.sunrise-sunset.org/json?lat=9.757452&lng=16.415384 2
    sensor:
      - name: 'Sun Tropic Sunrise'
        device_class: timestamp
        value_template: "{{ today_at(value_json.results.sunrise[:-3]).isoformat() }}"
      - name: 'Sun Tropic Sunset'
        device_class: timestamp
        value_template: >
          {{ today_at(strptime(value_json.results.sunset,'%I:%M:%S %p').strftime('%H:%M:%S')).isoformat() }}

alias: example
trigger:
  - platform: time
    at: sensor.sun_tropic_sunset
condition: []
action:
  ... etc ...

Reference: Time Trigger

EDIT

Correction. Template for sunset now correctly converts PM to 24-hour time.

#4

That code gives this response: (Result type: string)

2023-03-23 17:06:09+00:00
2023-03-23 17:06:09+00:00
2023-03-23 17:06:09

My rest sensors configuration looks like this:

  - platform: rest
    name: Sun_tropic
    json_attributes:
      - results
    value_template: "{{ as_datetime(value_json['results']['sunrise'].title()) }}"
    resource: https://api.sunrise-sunset.org/json?lat=9.757452&lng=16.415384&formatted=0
  - platform: template
    sensors:
      sun_tropic_sunrise:
        friendly_name: "Sunrise tropic"
        value_template: "{{ as_datetime(state_attr('sensor.sun_tropic', 'results')['sunrise'].title()) }}"
        entity_id: sensor.sun_tropic
      sun_tropic_sunset:
        friendly_name: "Sunset tropic"
        value_template: "{{ as_datetime(state_attr('sensor.sun_tropic', 'results')['sunset'].title()) }}"
        entity_id: sensor.sun_tropic
#5

Thank you! That looks like a good solution. Will try it when I have more time and energy.

#6

As an alternative, I use sun2, and create a binary sensor with this config:

- platform: sun2
  latitude: 9.757452
  longitude: 16.415384
  elevation: 163
  time_zone: <as required>
  monitored_conditions:
    - elevation: 
        above: -0.833
        name: Daytime

Then it’s very easy to create a simple automation from this:

- id: run_scene_at_sunset
  alias: Turn on lights at sunset
  trigger:
  - platform: state
    entity_id: binary_sensor.daytime
    from: 'on'
    to: 'off'
  condition: []
  action:
    blah blah

sun2 allows you to adjust how you define day and night in various ways - I use elevation as it’s most accurate for lights where I live, but you may want to tune it as you see fit.

#7

How does sun2 know it’s supposed to track the sun’s position? Does adding the features latitude, longitude, elevation and time_zone make home assistant automatically treat it as a sun “object” at the given location?

#8

Yes, sun2 is a specific custom component to do just this - I linked it above. Install in custom_components or via HACS or whatever.

#9

Oh, I missed the link.

#10

I used this last night and this morning the light went on just as planned! Thanks! BTW I added a timedelta to get it from UTC to my time by appending this:

..... .isoformat() + as_timedelta('02:00:00')

I’m sure the sun2 as recommended below would work just as well, but this is the one I went for.

#11

You’re welcome but it appears you have misunderstood the purpose of the Solution tag.

You marked your own post with the Solution ta using the solution I had suggested. It’s the community’s custom to assign the Solution tag to the first post that answers/resolves the original question/problem.

For more information, refer to guideline 21 in the FAQ.

#12

I just mis-clicked. :grinning_face_with_smiling_eyes: Corrected.

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