Unknown schedule - Self-testing
Standard self-testing emergency lighting products and products with STSelect automatically perform these tests, per code. However, the date and time these test are run are random, light by light. This is done so emergency lights under test do not all reduce illumination in emergency mode at the same time, which could be inconvenient to building occupants. Another reason for this is if a duration test was just performed, it will likely leave all recently tested products in need of charge. If power were to fail soon after testing, the devices wouldn't be able to light the area for the full 90 minutes.
Standard self-testing and STSelect products will attempt to delay testing if the room in which they are installed are occupied at the time of the test. These products detect if switched hot is present at the luminaire, indicating the lights are on. The product delays for a preset time, typically 8 hours, and checks again. These products will delay a set number of times before forcing the test to be performed, no matter the state of the switched hot. In short, within a month, all tests will be performed as required.