How the flip works
Each digit is a card split across the middle. When a number changes, the top half of the old digit folds down out of sight while the bottom half of the new one unfolds into place, the way a split-flap desk clock does. The digits only change when the time does, so with seconds off there is one flip a minute and the screen is still the rest of the time.
If your device is set to reduce motion, the cards swap digits with no animation at all.
If your device is set to reduce motion, the cards swap digits with no animation at all. There is no sound, so no tick or clack. A clock that sits still most of the time is also kind to a screen left on overnight, and the Dim slider lowers the whole display below what the device brightness allows.
Colour themes and dim levels
Ember is about 2700K amber on near-black, Candle is deeper and closer to 1900K, Mono and Daylight move toward white and blue-white, Night red uses dim red digits on pure black, and Paper reverses everything with dark ink on cream. Dim runs from full strength down to about a tenth, with finer steps at the dark end.
A flip clock as a screensaver
Left fullscreen with Keep screen on ticked, the page works as a screensaver for a spare monitor, a kitchen tablet or a TV. The time comes from the device clock, so it matches your phone, including daylight saving changes. For plain digits on black, see the black screen with clock; for a moving display, the DVD screensaver.