As per the news:
The drill will be held in southern Taiwan – Tainan, Kaohsiung and Pingtung County – between 1:30 p.m. and 2 p.m. on May 11
臺南市106年軍民聯合防空（萬安40號）演習正式時間訂於106年5月11日（星期四）13時10分起至14時30分止，需配合於演習期間暫停戶外活動課程。
The government will be holding the annual Wan-an No. 40 Air Raid Drill for southern Taiwan from 13:10 to 14:30 on May 11. Drills in the science park will involve the evacuation of people and vehicles, as well as the implementation of traffic control measures. All outdoor activities during the drill should be cancelled. Teachers, parents, and students, please note the related information.
In particular, the authorities request that people avoid dressing up for the ocassion:
