Why it works
Review cycles stall on the self-assessment step — it's easy to put off, and HR ends up nudging people one at a time. The prompt is the same every cycle, so a scheduled recurring email opens the season on autopilot and gives everyone the same clear ask. The freshness is in each person's write-up, not the email.
Make it yours
Match the cadence to your cycle (quarterly, twice a year, annual). Update the deadline in the subject line for each cycle, or keep it relative ("within two weeks") so it never needs editing.