i've done a clock using two 8 pin PICAXE chips, a 74HC595, eight UCN5841's an old car clock ticker for a 1ppS timebase and 8 common anode LED displays with a few extra passives and buttons for time setting
it will show the time to the second and keeps its time reasonably well plus i can use the serial from it to drive more of the display units for a synchronous clock plus it has hourly beep which passes through the serial controlling the remote displays. and a spinning widget which changes every second