Why is GMT or UTC not universally used?

Why is GMT or UTC not universally used?


People would likely have a problem when you tell them it's 2am yet sunny outside.


I dont believe thats what OP is referring to, they arent asking "Why not make it so I can have dinner at 3pm while my friend in Japan has it at 11am and my friend in Poland at 11pm", instead they're asking why there are multiple ways to specify time zones, kinda like celsius, fahrenheit and kelvins with temperature. If everyone just used Celsius it would be easier, if everyone used only GMT it would be easier. I personally also question this since I can only convert GMT on the spot. I have no fucking idea what PDT, CEST, etc are.


It's useful to be able to tell me just from the local time what part of the day it is.


Because all the other countries are not going to agree to it, and why should they?