In the October 1, 1904 Watchtower, page 298, the 587 BCE chronology issue is raised by a reader. Below are the final comments of a lengthy defense. I thought it worth sharing...
"A move of nineteen years, as the brother suggests above -- or for that matter a change of even one year -- would affect all the time prophecies of Vol. III. of the DAWN. The 1260 days, the 1290 days, the 1335 days, the 2300 days of Daniel, would all be thrown out of gear, out of the beautiful relationship shown in the Parallel Dispensations.
We all remember how we were thrilled when first studying we found that the parallels of dispensation showed that our Lord was due to be present in October, 1874, as the exact parallel of the beginning of his ministry and the “harvest” of the Jewish age; and how this thrill was intensified when we found the same date exactly marked by the Jubilee type; and how we almost shouted for joy when we found that Daniel’s “1335 days” ended at precisely the same date; and, finally, how we repeated over and over the Prophet's words, “Oh, the blessedness of him that waiteth and cometh unto the 1335 days.”
What a blessedness indeed ! As the Apostle intimated it would be, so we have found it, “Times of refreshing!” Take away these parallels, disjoint this testimony by changing any part of the chronology, and you have a still mightier work before you; -- the work of accounting for the rich spiritual food the Lord has been supplying to us since October, 1874 -- since the time of his presence, and in full accord with his promise that he would gird himself and become the servant of his true ones at his second presence and serve them “meat in due season,” sending it at the hands of his faithful servants. We have dealt with this subject at greater length than it may seem to deserve, believing that it may stimulate some to follow the Apostle's exhortation, "Let us give the more earnest heed to the things which we have heard, lest we let them slip."-Heb. 2: 1."