Persistent last changed sensor

[tom_l]

@Rourke

Isn’t that unnecessarily complex?

No it is necessarily complex. As you have pointed out, the last changed attribute is altered at restart.

To get the format you want will be even more complex:

Template to show days days / hours passed since switch on?

Try this: - platform: template sensors: greenhouse_last_changed: friendly_name: 'Greenhouse Last Changed' entity_id: - sensor.time value_template: > {%- set time = (as_timestamp(now()) - as_timestamp(states.switch.greenhouse.last_changed)) | int %} {%- set minutes = ((time % 3600) // 60) %} {%- set minutes = '{}minutes'.format(minutes) if minutes > 0 else '' %} {%- set hours = ((time % 86400) // 3600) %} {%- set hours = '{…