Renew the passport before you need it
Passports expire on a date you will not remember six years later. Many countries want six months of validity left. A reminder a year out is not too early.
When to start
Set a reminder 9–12 months before expiration. Include the expiration date in the message. Processing times move; the text is the prompt to check the current wait.
Once, then done
This is a once reminder. Complete it when you submit the renewal. You can then use the free slot for something else.