The daytime running light is about 1-2 seconds after the engine is started and switched off immediately as soon as you turn on still or low beam.
If you switch off the engine, it lights still pretty much 30 seconds of what I think does not function for a technical defect, but for such a deliberate "Coming Home". For me an absolutely useful highlight!
Conclusion: For the price, I can just recommend the device. Should it go naturally subsequently quickly broken, so I had to update the review. Currently, however, all is well!