‘scholar’:
If it was in the 4th year- 518 BCE then why was avision received two years earlier.
Pointless misdirection indicating you don’t understand this type of literature. The author wasn’t writing a diary as it happened. It was all written later. The ‘vision’ is a narrative device framing the purpose of the period - that had not yet ended in early 519BCE - as ‘denunciation’. Chapter 7 is quite clear about the timing of when 70 years of fasting were reached.
the temple was completed in 515 BCE
I correctly state on that page that it was near rather than in the year the temple was completed. I also clearly state, as does Zechariah, that 70 years of fasting is reached in Darius’ 4th year. None of this is particularly difficult. I suppose I could simply omit the part about the temple as it seems to confuse some of the dimmer readers.