In short: FEMA was slated to test out its "Presidential Alert" system for sending mobile notifications to everyone, on September 20. Now, FEMA has announced that it has been pushed back to October 3. This decision was made due to the severe weather that is hitting the east coast right now, with much of the east coast dealing with Hurricane Florence. And doing a test during that time is definitely not a good idea, especially for those in the affected area.
Background: As is indicated by the name of this alert, it is an alert that the president could send to all cellphones in the US, regarding public emergencies. So if there is a hurricane coming, the President could warn everyone and tell everyone to get out. This is part of the WEA (Wireless Emergency Alerts) system that has been available for quite a few years, and used sparingly. The test will have a header that says "Presidential Alert" with the text "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed." This test will take place at 2:18pm Eastern time on October 3. Now while many are able to opt out of weather and AMBER alerts, these tests cannot be opted out of. This test is going to for sure startle some people, and it will ring regardless of whether your ringer is turned off or not, as is the case with all of these wireless emergency alerts.
Impact: Moving back this test will mean that it'll be longer before the President can actually use this to send out alerts to the citizens of the United States. But it's also the right thing to do, especially since FEMA is working in North Carolina, South Carolina, Maryland, Virginia and a few other states right now to get families back on their feet after Hurricane Florence came through.