Time Clocks adds three clocks that control time! For survival mode, all recipes can be unlocked by getting a vanilla Clock. For creative mode, using /tick will mess the clocks up, so try not to use /tick with this mod.

Freeze Clock

The Freeze Clock freezes or unfreezes time. Crafted by surrounding a Clock with Packed Ice. In the action bar, it says whether time is frozen.

Speed Clock

The Speed Clock sets time to 2x speed or 1x speed. Crafted with a clock in the middle, redstone on the top row and left middle, and emeralds in the rest of the grid. In the action bar, it says the speed of time.

Slow Clock

The Slow Clock sets time to 1/2x speed or 1x speed. Crafted with a clock in the middle, diamonds on the top row and left middle, and lapis in the rest of the grid. In the action bar, it says the speed of time.

These aren't the names the clocks have in-game, but the textures are the same as they are here. Happy time controlling! 

The clocks work by using /tick automatically. Also you can do stuff like this: