Can 'by' be replaced with 'around', 'before' or 'in' in the sentence "japan pushes back budget surplus target by two years due to coronavirus"?

this is my sentence ‘japan pushes back budget surplus target by two years due to coronavirus’ why the preposition is ‘by’?
I looked up and understanded the usage "by + a certain time" as:

Blockquote
"By the year" here means "before the year" or "no later than the year":
By the year 1582, scientists pointed out that the calendar was 10 days behind the sun. (Before the year 1582 starts)

that is what I already know. but I have never met ‘by’ followed by a period in this phrase ‘by two years’.
here are my guess:

• maybe in this sentence BY means ‘approximately; uncertain; about; around’,because

Blockquote
The "core" sense of by is near, beside, but in contexts where movement (through space or time) is relevant, there’s a metaphorical extension to this definition

so this sentence can be rewritten as ‘japan pushes back budget surplus target around two years due to coronavirus’. is it ture?

• because the predicate is ‘pushes back’, so the word ‘before’ is reasonable. so this word can
  be rewritten as ‘japan pushes back budget surplus target before two years due to coronavirus’.is it ture?
• I think ‘by two years’ can be replaced with ‘in two years’ because the latter phrase is so common and the semantics are unchanged.is it ture?
  thank you in advance.