Benjamin Haviland, son of William Haviland & Hannah Hicks, was born 3 Apr 1659 in Newport, RI.  The Genealogical Record of the Saint Nicholas Society records his birth in the year 1660.  The Hudson-Mohawk Family Memoirs records his birth date in 1654, but the 9 could have been mistaken for a 4 in a transcription error. 
He married in Portsmouth, RI to Abigail Mott , daughter of Adam Mott & Mary Lott. 
"The first five children named below are mentioned in the census of Flushing, taken 1698, together with wife Abigail and also John Heaviland, wife Sarah and son John; also William Benger, wife Elizabeth, sons John, Jacob and Elizabeth and a part of this which I cannot understand is that they are all listed under the French Inhabitants." 
?Elizabeth (See her notes. This is speculation due to a suspected error by Josephine Frost. It is supported by age calculations not evidence. It is possible she was born directly after the 1698 New York Census in that same year.)
He relocated from Newport, RI to (on Long Island) ca 1694.
"Dec. 27, 1711, just twenty-three days after he sold out in Flushing he purchased of John Yates for 160 pounds, 400 acres in Rye, Westchester Co., N. Y. Recorded Sept. 1, 1718. The original deed yet exists and is owned (1894) by John Haviland of Plainfield, N. J., who says that Benjamin in 1724 built the first frame house in Purchase, N. Y., all others previous to that time being of logs. This house was burned during the Revolution. It stood at the top of the hill on the Old Purchase road above the house of Charles and Phebe Carpenter. (June 14, 1700, Caleb Heathcote sold a two story frame house, shingled and with a brick chimney to Joseph Haviland, which was located in Westchester.)" 
Death & Burial
According to several sources, Benjamin died 20 Apr 1726 .
But Frost's The Haviland Genealogy conflicts with this by a few months. On page 46 she wrote, "BENJAMIN HAVILAND, son of William and Hannah (Hicks) Haviland, b. Rhode Island, about 1659, d. Rye, N. Y., 31 of 6 mo., 1726..."  This death date is clearly incorrect, as there are 30 days in June, not 31. She probably meant July: for on page 53 of that book, she seems to write the date she actually intended: "Benjamin is said to have died at Rye31 of 7m 1726 as a ministering Friend."  She did not record her source for this date, but since she wrote, "is said to have died," we believe she was basing her date on the History of Southern NY written by Frederick Haviland, on whom Frost leaned heavily during her research.
The New York Monthly Meeting records has a Benjamin Haviland of Rye dying on Sep 31 1726, though we don't know for sure if that is the same person, and possibly a 7 could have been mistaken for a 9 in the writing, and if so, it would corroborate Frost. On the other hand, a 9 could also be mistaken for a 4, corroborating the other sources.
It may be possible to confirm family relationships with Benjamin by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Since Benjamin2 Haviland signed all his known grantor deeds by mark, the signature on this page has to be that of his namesake son, who was then (1709) presumably in his late teens, certainly old enough to have signed as a witness of the Bowne–Smith marriage.
In the original Flushing Monthly Meetings record of Benjamin2 Haviland's death, the number of the month is overwritten, presumably six over seven rather than vice versa, since the seventh month, then September, had/has only thirty days. Benjamin's precise date of death is therefore 31 6th month [August] 1726.
May I suggest that, in writing "31 of 6 mo., 1726", Ms. Frost was likely quoting a contemporary source, which in 1726 would have expressed a date in the old style, wherein March is the 1 mo. So her date for Benjamin's death is, in new style, 31 August 1726. A common source of confusion with any pre-1752 dating, but not an error on her part. Of course, that does not explain the 31 of 7m 1726 date on page 53 that he is said to have died in the Friends Records at Produce Exchange.
I agree, until a reliable source has been found the only commonality amongst the proposed dates of death is 1726. Of the searches I did I came up with 4 different dates, however none of the sources are what I would call reliable.
I would like to propose that we use simply the year 1726 for the death of Benjamin Haviland for now, since we have one secondary source that has 31 Jul 1726, one primary source that has 31 Sep 1726 (but without certainty as to whether it's the same Benjamin), and a few more sources that record 20 Apr 1726. The profile currently has 31 Aug 1726, which I have not seen before and the source doesn't seem to be referenced. However I don't want to arbitrarily change that without input, since I don't know what the source is If anyone agrees, let's do that, and reference 31 Aug 1726 in the Biography (but I'd like to know the exact source of that proposed date if it can be obtained).