Bills, before they are late
Autopay fails. Paper sits in a pile. A text a few days before the due date is a cheap insurance policy.
Due dates are local
Set the reminder in your timezone for a weekday morning you actually look at your phone. Recurring monthly reminders keep the same day each month; if a month is short, the last valid day is used.
What to write
Name the bill and the action: “Pay the electric bill” or “Confirm rent left the account.” Do not put account numbers in the text.