In many ways and many forms, Elohim anciently conversed with our fathers by the prophets, but in the latter days He has conversed with us by His Son whom He has constituted heir of all things, and by whom He has made the worlds. Hebrews 1:1-2 (AENT)
1599 Geneva Bible
[SUP]1 [/SUP]At sundry times and in divers manners God spake in the old time to our fathers by the Prophets: in these last days he hath spoken unto us by his Son,
[SUP]2 [/SUP]Whom he hath made heir of all things, by whom also he made the worlds,
The latter days in first mentioned in Genesis 49:1, "And Jacob called unto his sons, and said, Gather yourselves together, that I may tell you that which shall befall you in the last days."
Then in James 5:3, "Your gold and silver is cankered; and the rust of them shall be a witness against you, and shall eat your flesh as it were fire. Ye have heaped treasure together for the last days."
and also in 2 Peter 3:3 "Knowing this first, that there shall come in the last days scoffers, walking after their own lusts,"
To me the "later days" seem to take in "all" of the New Covenant time period, including the 2nd coming of Christ.
The first part of the general proposition of this Epistle, is that the Son of God is indeed that Prophet or teacher, which has now actually performed that, so God, manifested in Christ Jesus, and in shadows signified by his Prophets, has fully opened his Father’s will to the world.