How many days it take to complete java

Answer 1

Depends on how much effort you're putting in learning it

Answer 2

The more you put in the more you get out

Answer 3

It depends on what you wanna do

Answer 4

Do you mean complete the course that is on SoloLearn? You can complete it in an hour.
If you want to comprehend the whole language, it takes years to do it.