Possible fix is attached.

Description and steps to reproduce:

At noon (time 6000), the clock spins once, under certain conditions.

Slow way, no /time commands

1. Start a world, /give yourself a clock.
2. Allow 5 minutes to pass, without advancing /time.
3. You won't see the clock spin at the first noon.
4. Allow 20 more minutes to pass, without advancing /time.
5. The clock will spin around at any noontime after the first noon.

Faster way

1. Start a world, /give yourself a clock,
2. /time set noon
   • I reproduced this most reliably when I started near noontime. I couldn't tell you how near to noon is close enough to trigger this 100%, but setting to noon definitely works.
3. Close out of Minecraft entirely, relaunch, and open that world again.
4. /time set 5900
   • .. or any full day after: 29900, 53900, etc
   • it spins to get to this time, but this is not the bug.
5. The clock will spin around at noontime.

If you play around and issue too many /time commands, such as /time set day, the spinning at noon can stop happening – unless you relaunch Minecraft, then you can make it happen again.

Wasn't happening in 1.8.8, but started happening in the first 1.9 snapshots.

Possibly related to MC-83905 where the compass spins when the player faces south.