What is the date of the restoration of the Melchizedek Priesthood?

There is a narrow May 15 to 30, 1829 ordination window

Knowing that the prophet already had the Melchizedek priesthood prior to the organization of the church we can look at the following clues of the May 15 to 30, 1829 ordination window in order of progressively narrowed parameters:

1. Year 1829: There is a manuscript in Oliver Cowdery’s handwriting recording part of D&C 18: saying, "Written in the year of our Lord & Saviour 1829." ^[1]
2. June 1829: In D&C 18:9 we read "And now, Oliver Cowdery, I speak unto you, and also unto David Whitmer, by the way of commandment; for, behold, I command all men everywhere to repent, and I speak unto you, even as unto Paul mine apostle, for you are called even with that same calling with which he was called."
3. Before June 14, 1829: Oliver Cowdery wrote a letter to Hyrum Smith. The letter has some wording that quotes and refers to section 18 in the D&C. ^[2]
4. Before June 1, 1829:
5. Joseph Smith said that he, Emma, Oliver and David Whitmer traveled to the home of Peter Whitmer Sr. "In the beginning of the month of June." ^[3]
6. David Whitmer is quoted as saying "The translation at my father’s farm, Fayette Township, Seneca County, New York occupied about one month, that is from June 1, to July 1, 1829." ^[4] If those dates are exact then the Prophet was in New York during the entire month of June.
7. Orson Pratt asked David Whitmer, "Can you tell the date of the bestowal of the Apostleship upon Joseph, by Peter, James and John?" To which he replied: "I do not know, Joseph never told me." From this we can tell that the visitation either:
   1. Happened during the traveling when Joseph and Oliver were away from David and did not tell him about the occurrence (their trusted friend with whom they shared many other events).
   2. Happened at another time than their travel from Harmony to Fayette.

Why did several years pass before Oliver Cowdery talked about the priesthood restoration?

We don't know when Oliver first mentioned the priesthood restoration to anyone - we only know when he first put it in print

It should first be noted that many critics ignore versus in the Book of Mormon that refer explicitly to the priesthood:

• Alma 4:20 - Alma was "confined [to the] high priesthood of the holy order of God..."
• Alma 5:3 - Alma the younger is consecrated to be a high priest over the church of God by his father, Alma, who had power and authority from God to ordain.
• Alma 13 - an explication of the power and function of the High Priesthood of Melchizedek.
• Mosiah 18:17 - only those baptized by the "power and authority of God" are added to the Church
• 3 Nephi 11:25; 12:1 - the 12 Nephite apostles receive power and authority to baptize

These are the earliest printed mentions of the priesthood. We don't know when Oliver first mentioned the priesthood restoration to anyone - we only know when he first put it in print. But consider this: If Oliver was covering up a fraud on the part of Joseph Smith when he talked of receiving the Aaronic and Melchizedek Priesthoods, then why didn't he expose the fraud after he fell into disagreement with Joseph Smith and was excommunicated from the Church? Why, in fact, did Oliver continue to insist that the events related to the restoration of the Priesthood actually happened?

The implication is that Oliver was dishonest, yet his associates during the time that he was a lawyer after leaving the Church viewed his character as "irreproachable". Harvey Gibson, a political opponent of Oliver's, and another lawyer (whose statue now stands in front of the Seneca County courthouse) wrote:

Cowdery was an able lawyer and [an] agreeable, irreproachable gentleman. ^[5]

Webster's 1828 dictionary defines "irreproachable" as "That cannot be justly reproached; free from blame; upright; innocent. An irreproachable life is the highest honor of a rational being." ^[6]

Oliver wrote the following to Phineas Young two years after Joseph's death, well after he had left the Church:

I have cherished a hope, and that one of my fondest, that I might leave such a character, as those who might believe in my testimony, after I should be called hence, might do so, not only for the sake of the truth, but might not blush for the private character of the man who bore that testimony. I have been sensitive on this subject, I admit; but I ought to be so—you would be, under the circumstances, had you stood in the presence of John, with our departed Brother Joseph, to receive the Lesser Priesthood—and in the presence of Peter, to receive the Greater, and looked down through time, and witnessed the effects these two must produce,—you would feel what you have never felt, were wicked men conspiring to lessen the effects of your testimony on man, after you should have gone to your long sought rest. ^[7]

Painesville Telegraph (1830): "Cowdry claims that he and his associates are the only persons on earth who are qualified to administer in his name. By this authority, they proclaim to the world"

Painesville Telegraph, 7 December 1830:

Mr. Oliver Cowdry has his commission directly from the God of Heaven, and that he has credentials, written and signed by the hand of Jesus Christ, with whom he has personally conversed, and as such, said Cowdry claims that he and his associates are the only persons on earth who are qualified to administer in his name. By this authority, they proclaim to the world, that all who do not believe their testimony, and be baptized by them for the remission of sins . . . must be forever miserable.^[8]

Painesville Telegraph (1830): "The name of the person here, who pretends to have a divine mission, and to have seen and conversed with Angels, is Cowdray"

Painesville Telegraph, 16 November 1830:

About Two weeks since some persons came along here with the book, one of whom pretends to have seen Angels, and assisted in translating the plates. He proclaims the destruction upon the world within a few years,--holds forth that the ordinances of the gospel, have not been regularly administered since the days of the Apostles, till the said Smith and himself commenced the work . . . . The name of the person here, who pretends to have a divine mission, and to have seen and conversed with Angels, is Cowdray."^[9]

The Palmyra Reflector (1831): "Jo Smith had now received a commission from God...Cowdery and his friends had frequent interviews with angels"

The Palmyra Reflector, February 14, 1831:

They then proclaimed that there had been no religion in the world for 1500 years,--that no one had been authorized to preach &c. for that period—that Jo Smith had now received a commission from God for that purpose . . . . Smith (they affirmed) had seen God frequently and personally—Cowdery and his friends had frequent interviews with angels.^[10]

Reverend Taggart (1833): "Joe Smith...told them he had seen Jesus Christ and the Apostles and conversed with them, and that he could perform miracles"

Reverend Richmond Taggart to Reverend Jonathan Goings, Cleveland, Ohio, March 2, 1833:

The following Curious occurrence occurred last week in Newburg about 6 miles from this Place [Cleveland, Ohio]. Joe Smith the great Mormonosity was there and held forth, and among other things he told them he had seen Jesus Christ and the Apostles and conversed with them, and that he could perform miracles.^[11]

See FAIR Evidence:
More evidence related to the restoration of the priesthood