A frame accurate clock ticks down (with audio) the final 25 seconds to the 12 o'clock position in real time - an involved face design with luminous 5 second indicators and white second marks along with 1/5th - 1/3rd and 1/12th of a second indicators.
The white arm tracks whole seconds.
The red arm tracks 1/5th of a second.
See also 'Classic Countdown Clock / Simple' for a simplified countdown design without the sub-second indicators.