The 21-day DPN clock starts on the issue date—not when it hits the desk....

https://www.acid-bookmarks.win/the-21-day-dpn-clock-starts-on-the-issue-date-not-delivery-distinguishing

The 21-day DPN clock starts on the issue date—not when it hits the desk. Knowing the difference between lockdown and non-lockdown notices is critical for immediate advice. This guide breaks down the nuances so you can triage fast and keep options open.