Arduino Uno or Nano with LCD 1602 clock. Large figures are made of 8 custom created characters, each number is made of 6 characters.
The clock is as accurate as the built in crystal. 1 second time base is division by timer1 and timer2. Link between pins 5 and 3 connects output of timer2 to input of timer1.
Seconds are displayed in normal size number.
the pushbuttons set the hours and the minutes.
For more info http://www.moty22.co.uk/