If you’d like to participate in a test of the Emergency Alert System, turn on your TV on September 28th at 2:20 PM EDT.
You can read more about this on the TDI site. https://tdiforaccess.org/2016/09/eas-test/
If rescheduling is necessary, there is an alternate date of October 5,2016.
Also check out all the links on the TDI blog post for more information. Especially this one to submit comments after the test. https://www.fcc.gov/general/public-safety-support-center