Everything will be displayed above your hotbar, but only one Display can be shown at once.
To show the display you want, you need to run a function (for more information see the text below).

The following things are also listed in a instruction book, which will be given to ever players who joins a world the first time.
 

• World Timer
  This clock counts every second you played in a world and displays it in days, hours, minutes and seconds.
  To display this clock, type this in your chat: /function world_timer
   

• Clock
  This clock shows the ingame daytime and counts every quarter of an hour.
  Even when you sleep, the clock stops to count and is set to the correct time.
  Also the current weather will be displayed at the right side: a sun/moon meas clear weather, a cloud with rain means raining and a cloud with a lightning means storming.
  To display this clock, type this in your chat: /function clock
   

• Stopwatch
  With this clock you can simply count the time you need for something.
  type /function start in the chat to start it
  type /function stop in the chat to stop it
  type /function reset in the chat to reset it
  To display this clock, type this in your chat: /function stopwatch
   

• Timer
  This clock is a timer, which means that you can adjust a time (in hours, minutes and seconds) and after you started the timer it counts down the time untill zero seconds.
  The time must be adjusted with the scoreboard command (the exact command will be shown in the chat when you display the timer).
  After you adjusted the time,
  type /function start in the chat to start it
  type /function stop in the chat to stop it
  type /function reset in the chat to reset it
  To display this clock, type this in your chat: /function timer
   

• Debug Display
  This display shows you some more information which can be important especially in survival mode:
  - Clock again (with weather)
  - the Biome you are in
  - Compass and the coordinates direction you are facing
  - Light level at your position
  - RSS (Redstone Signal strength) at the block you are facing
  - your Last-Death-Coordinates (for this I also added a death counter, which is 
     displayed as a sidebar-scoreboard)
  - your own Player-ID near the death-cords (needed for the graves)
  To display the debug display, type this in your chat: /function debug

  Unfortunately it seems, that there is a bug with the identification of some new 1.18 biomes in this Minecraft version.
  At the moment I can`t track cheese, noodle and spaghetti caves.
  With jagged, frozen and stony peaks there is a similar problem, nevertheless I found a trick to track them, but it`s still not possible to differentiate between jagged and frozen peaks.
  RSS: It was really hard to get this to work and it`s still not perfect, because it`s very difficult to target the right block the player is facing on when you have multiple redstone dust in a line. So the best way to use this feature is to stand/fly a bit above the block you want to aim to. If you try to aim on a block that is nearly horizontal to your view it often targets the wrong block.
   

• I tested the normal version with my smartphone (6 inch). It`s display was too small to show the long debug-display.
  So I added a second version for small devices, where the debug-display is a bit smaller:

• Death-Counter:

License for this addon:

• The rest of the graves-behavior is made by myself.
  The grave has gravity, so it will fall down if you die in the air or under water, but I made it so that it will swim on lava if you die in lava.
  Unfortunately the grave can`t get the name from the player who died (at the moment I found no way to solve this problem, except making a script and I didn`t want to add a script to the addon) and that`s the reason for the Player-ID. Every player who joined the world/realm will get a player-number (for example "P 1" in your debug-display means "Player 1") and if a player dies, the grave will be named with "Player and the players number", so that the grave is related to this player. So the grave can only be opened and destroyed when the related player is in a radius of 3 blocks (but then every player can access the inventory or destroy the grave).
  But there is still one problems I can`t fix:
  For every player-number I had to add specific commands and so maximum 50 different players should play on one world/realm. For all players with the number 51 or more, the Grave-System can be buggy.

  Because of this problem, I added the possibility to deactivate and activate the graves (normally it`s activated, for more information see the point below).
   

• for player who want a bit more challenging survival gameplay I added thirst and temperature to the addon
  You can turn this part off and on. Normally it`s deactivated.
  To activate/deactivate it, go to your active world behavior packs. Click on the "Debug and Clocks Addon" and then on the little gear. A little control panel will open, where you can choose between "More Survival" (means with thirst and temperature) and "Less Survival" (without thirst and temperature):
• 1.

• 2.

• 3.

• If you activate "More Survival", you will get information about your temperature and thirst in the chat every 20 seconds or you display them always above your hotbar with /function temp_thirst .

                                                                   or

• > If the thirst is too low you get negative effects, so it has to be refilled from time to time by standing in any water block or a cauldron with water. Also you can drink a water bottle or a milk bucket.
  In a desert/mesa, jungle and savanna or in the nether  you have to quench your thirst more often.

  > If the temperature is too high or too low you also get negative effects.

  temperature goes high:
  in biomes:
  - desert and mesa biome (at day)
  - jungle (at day)
  - savanna (at day)
  - all nether biomes
  near blocks:
  - torch
  - campfire
  - lantern
  - lit furnace
  - lit blast furnace
  - lit smoker
  - magma block
  - lava/flowing lava
  - fire
  - soul campfire
  - soul lantern
  - soul torch
  - soul fire

  temperature goes low:
  in biomes:
  - ice biome
  - hills
  - ocean
  - every other biome (at night, jungle and savanna very slow)
  - in caves
  near blocks:
  - snow/snow layer
  - ice/packed ice/ blue ice
  - water/flowing water and cauldron with water (in ice, hills and ocean biomes)

  temperature goes to optimum:
  - in every biome I didn`t mention before (at day)
  - in the end
  - water/flowing water and cauldron with water ( in every biome except in ice, hills 
     and ocean biomes)
  - thirst refill with bottle and milk bucket

   

• hide all clocks and debug displays
  To hide all clocks, so that nothing will be displayed above your hotbar, type
  /function hide in your chat.

   

• other information
  The world timer and the clock always count, even if you don`t display them.
  However this don`t work with the stopwatch and the timer. So when they count, but you change the clock, they don`t reset but stop counting untill you display them again.

  For Multiplayer I also added a One-Player-Sleep-System.

   

You can modify and share this addon or use my original version for other creations but don`t use it as a form of business and please give me credits by placing a link to me.