Clock

"Keep track of the scary time! A craftable watch lets you know when it's safe to emerge from the caves."

- The Halloween Update promo poster

Clocks (sometimes called watches), are items that display the current in-game time by displaying the sun and the moon's position relative to the horizon.

Trading
A single clock can be bought from a librarian villager for 10 to 12 emeralds as part of their tier 3 trades.

Usage
The clock consists of two halves, a day side and a night side. These spin slowly to indicate the time of day, corresponding to the sun or moon's actual position in the sky. The player is able to sleep a few seconds after the clock shows exactly dusk.

Clocks will still show the proper time hen viewed in any way, including as a dropped item, in a player's hand, in any inventory or the crafting table, or in an item frame.

Clocks do not work in the Nether or the End, the dial will instead rewind rapidly showing random times of the day, making it useless for determining the time.

Trivia

 * A clock can be viewed under the item statistics page, as long as one has made a clock at some point in the past.
 * If sleeping with a clock in your hand, upon waking, or the time is changed through the commands, the clock dial will spin rapidly to catch up.
 * After completing 100 day-and-night cycles in the Console Edition or Windows 10 Edition you get an achivement and, on the Xbox 360 Edition, you are awarded a miniature clock wristwatch for your Xbox Live avatar to wear.

Uhr Reloj Montre Óra 時計 시계 Klok Zegarek pt-br:Relógio Часы 钟