Before 1 January 2024, will a nuclear device be detonated somewhere in the world?
As of the launch of this question, it is generally believed that no fewer than nine countries in the world have nuclear weapons (Arms Control Association, Federation of American Scientists). Whether a detonation is characterized as a test, an accident, a warning, or an attack would be immaterial, and the detonation of a device in orbit around Earth would count. A radiological device (aka "dirty bomb") would not count (Mass.gov). Whether or not a nuclear device has been detonated will be determined using credible open source media reporting. That determination must be made during the question's open period to count, as well as the detonation.