Clock doesn't work

When using a clock it mostly shows the incorrect time. I.e. night when it's day etc. Sometimes the clock will skip backwards. This has effected all clock in game.

I have tried this both in SP and on our LAN server with the same effect. I use Majic Launcher, Optifine and Old faithful 64. I have disabled all of these to see if they were causing it but it's the same in vanilla.