Air raid sirens will be tested outside Beijing's Fifth Ring Road on September 19.

September 19 this year is National Defense Education Day. On the morning of that day, Beijing will organize an air defense alarm test, and conduct corresponding training drills as usual. The test area covers administrative regions outside the Fifth Ring Road in Beijing. The Beijing Municipal National Defense Mobilization Office reminds citizens and temporary visitors to Beijing to maintain normal work and life order after hearing the alarms. According to the notice, this air defense alarm test will sound in sequence: "pre-alarm," "air raid alarm," and "all-clear," with a 7-minute interval between each alarm signal. From 10:00 to 10:03, the pre-alarm will sound: 36 seconds on, 24 seconds off, repeated 3 times, lasting 3 minutes. From 10:10 to 10:13, the air raid alarm will sound: 6 seconds on, 6 seconds off, repeated 15 times, lasting 3 minutes. From 10:20 to 10:23, the all-clear will sound: a continuous 3-minute tone.