Ontario's Alert Ready test is Wednesday at 12:55 p.m.

A routine, pre-scheduled test of Canada's national emergency alerting system will take place Wednesday, Nov. 18, according to Alert Ready and Public Safety Canada. The test is listed on the published national testing schedule and is not related to Friday's disruption in U.S. air traffic.

Public Safety Canada says a test of the National Public Alerting System, known publicly as Alert Ready, will be sent out that day in all provinces and territories over wireless networks, television and radio. Canadians will receive a test message from their provincial or territorial government, the department said. The same Public Safety Canada page says public alerts are issued over compatible wireless devices, cable and satellite television and radio.

In Ontario, the test is scheduled for 12:55 p.m. EST, according to the official Alert Ready testing schedule.

Alert Ready's official support page says people cannot opt out of receiving test alerts. The Alert Ready website also asks the public not to call 911 for information about the test, saying that using 911 for non-emergency calls could delay help for people experiencing real emergencies.

Sources: Alert Ready testing schedule, Public Safety Canada, National Public Alerting System, Alert Ready, Alert Ready, "Can I opt-out from receiving test alerts?".