Hi Robert, welcome.
To which post you’re replying to?
When you responded to my post:
I suggest to discuss script issues in the topic of the script I linked to.
I’m over 664 months old 
In Homey language, 664 months means, when no last seen value is found, it just returns 1-1-1970 as value.
(No clue who came up with that date).
Also, last_seen timestamp is not always the real last seen moment
