I didn't use it at all because even when it's plugged in, the time display with the projector is not permanent and only happens if you press the switch.

I bought two. One for the country house and one for home. It has a large screen so that someone with vision problems can see it without glasses. However, the most important thing is that it reflects the time on any fixed point with very good resolution by magnifying it. So, when you wake up in the middle of the night and don't know what time it is, with a glance at the ceiling, you see the time and if it's early, you go back to sleep.