How Calculate Elapsed time since input_datetime updated to trigger automation?

Configuration
,
1

How could I trigger an automation when X minutes has passed since the input_datetime helper was updated?

I have a helper datetime variable “input_datetime.lastupdated”
I updated it with the following from an automation

service: input_datetime.set_datetime
metadata: {}
data:
  datetime: "{{ now().strftime('%Y-%m-%d %H:%M:%S') }}"
target:
  entity_id: input_datetime.lastupdated

States shows input_datetime.lastupdated is “2024-07-06 19:22:03”

I want to trigger an automation when 10 minutes has passed since the input_datetime helper was updated? I was thinking I could create a template sensor in template.yaml file but struggling with the syntax for that – other suggestions?

2 
trigger:
  - platform: state
    entity_id: input_datetime.lastupdated
    to: ~ # == NULL, which triggers on state changes, not attribute changes. 
    for:
      minutes: 10
5

thanks for the quick response. that looks more simple than I was thinking. give me context as to where this code goes and how I use that to trigger an automation if 10 minutes has passed since this was updated “input_datetime.lastupdated”

6

It’s a trigger. It goes in the trigger section of an automation. It does what you asked.

7

Thank you for your help. After some messing around, I got it to work. I learned a couple new things about triggering automations.