Quote fromSince redstone clocks are based on the renderer's speed, I believe, it makes it difficult to synchronize.
However, it's possible that the day/night cycle is based on the renderer's speed as well, so that means it would be possible to make a big "big ben"...
I'll look into it.
This is accurate. The redstone processing does have issues if the client begins to lag. Additionally, if you ever move too far away from the clock, and chunks unload, it will become wrong as well.
I know these things because I already made a 12 hour digital clock =)
EDIT: http://www.minecraftforum.net/viewtopic ... 50#p330044
The link, in case anyone's interested.