Automation trigger "3 days after a sensor, at 4:00 AM"

i’m trying to set an automation that fires up 3 days after my HA latest reboot, but at a specific hour of the night.

My hardware is slow and unsupported and sometimes RAM gets filled and a restart of HA is needed.
Originally I did an automation that fires up every three nights at 4:00 AM but sometimes I restart HA manually for changing some config and the nightly restart becomes useless. So my idea was to create a trigger that adds 3 days to sensor.uptime PLUS… “some hours to reach 4 AM”.

Any help with the code?
Thanks :slight_smile:

Create a Calendar event.

system monitor has sensor.system_monitor_last_boot
create a trigger at your chosen reboot time and see if the last boot time is greater than 3 days.

by the way, if your issue is that it craps out when ram gets filled, system monitor has info about ram usage and available swap. instead of doing a random reboot at some time, you could trigger off low ramp/high swap or something more directly the problem.

no, i mean sensor.uptime
I don’t need to reboot my hardware, only HA process
But this is not important, I need to understand how to do something at sensor.uptime + 3 days + some hours until 4 AM

my actual test trigger is:
{{ (states(‘sensor.uptime’) | as_datetime + timedelta(days=+3)).isoformat() }}

But this will reboot my HA at bad hours

I wish to understand how to do better templates as it is a totally new language for me, my idea was to convert sensor.uptime to a simple YYYY-MM-DD trimming out the hours and minutes, but maybe there is a better approach.
So far I was able to create this:
{{ (states(‘sensor.uptime’) | as_datetime + timedelta(days=+3)).isoformat() }}

For instance I did a HA reboot (only my docker instance, not the whole hardare!) at 18:15 today (february 17) and I want to automatically restart HA on february 20 at 00:00.
If tomorrow I will restart it manually to adjust some configuration, the automation should restart HA on february 21 instead of 20

same problem, how to set a calendar event 3 days after a sensor state plus some hours to 4 AM?
i need some formula that transforms this:
{{ states('sensor.uptime') }}
which now is: 2024-02-17T20:41:17+00:00

to 2024-02-20T04:00:00+00:00

i get that you’re trying to do all the math to set a time and then prob create a trigger on that time. but i’m still thinking that’s overly complicated. does this do what you want and much simplier in 1 automation? no calendar event, no additional automation, etc.

  - platform: time
    at: "04:00:00"
  - condition: template
    value_template: >
      {{(now() - as_datetime(states('sensor.system_monitor_last_boot'))).days >
      3  }}
  - service: hassio.host_reboot

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to my second point, you said you need to reboot when the ram gets low. how about this to reboot when memory goes below 128k (or pick your threshold):

  - platform: numeric_state
      - sensor.system_monitor_memory_free
    below: 128
condition: []
  - service: hassio.host_reboot
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thank you this solution works :slight_smile:
replaced with sensor.uptime and works for me