Clocks are decorative blocks placed on walls that can be used to tell time. The time on the clock is based on the time of the Minecraft day; time 0 (dawn) is 6:00 A.M. In order to retrieve a placed clock, a pickaxe must be used. There are currently twelve colors of clocks, red, green, blue, yellow, orange, white, brown, purple, pink, cyan, gray, and black! You can find each of their crafting recipes below. The vanilla clock can be obtained by defeating wild Hypno.
Until Pixelmon 6.3.0, there was only two variants of clock colors. They came in blue and pink varieties based off of the wall clock in the player character's room in Pokémon Ruby and Pokémon Sapphire!