[How to use mixins?]

How?? I don't know the method that can change time.

[How to use mixins?]

I want change how is the time manipulated when player is sleeping

[How to use mixins?]

I would like to change sleep mechanic.

[How to use mixins?]

Hello. I've tried to change an core mechanic for my mod. 

I've got information about that mixins can change methods of core mechanics. However on internet there is lack of information for it.

If anyone here know how to use them. I would be thankfull if you explain. I'm using 1.16.5 forge version