The debug screen is triggered when the F3 key is pressed. It shows the chunk cache, the memory usage, various parameters, the player's map coordinates and a graph that measures the game's current frame rate.
Real time
Minecraft time
50 seconds
1 hour (60 minutes, 3600 seconds)
1 minute
1 hour and 12 minutes (72 minutes, 4320 seconds)
20 minutes
1 day
1 hour
3 days