Put the summary of the bug you're having here
What I expected to happen was...:
I put /gamerule doDaylightCycle off to fight mobs and expected the moon to freeze in it's position.
What actually happened was...:
The time was frozen but the moon was slightly twiching up and down.
Steps to Reproduce:
1. go into creative mode and do /time set 14000 or /time set night.
2. Once the sun is completly down, do /gamerule doDaylightCycle off.
3. Look and the moon and notice that the moon is slightly twiching up and down, I'm inferring that the moon is trying to do it's cycle.
*It might do it with the sun as well, I'm not sure.
I think this may actually be an unintentional, intended feature. Basically the game continues to try and move time but the false just tells it from when you set it keep it there plus or minus a tick, making it twitch slightly. Its kind of like when a bukkit server is set to keep the daylight constant as it used to/still does the same thing.