For His Glory said -
This verse shows us that the timing from Ezra to the cross was 490 days as within that time Ezra was reestablishing the law in Jerusalem until Jesus had fulfilled the end of transgression, made an end to sin, made reconciliation for iniquity and bring everlasting righteousness and to seal up the prophecy to fulfill the law through the cross.
490 Days?
So all the generations from Abraham to David are fourteen generations, from David until the captivity in Babylon are fourteen generations, and from the captivity in Babylon until the Christ are fourteen generations.
Matthew 1:17
That's 560 years from the captivity in Babylon to Christ.
The captivity in Babylon was 70 years.
The command came after the Babylonian captivity.
That brings us to 490 years from the going forth of the command to Christ.
When the scriptures says "Christ", it is referring to the birth of Christ.
So as anyone can see, there is a problem with assuming there is no gap in the time line.
The first gap occurs at the 7th. Week.
JLB