The 607/ 587 BC or more accurately the 607/587/586 BC debate is very important for it involves Bible Chronology and its relationship to Eschatology and Prophecy.
587/586 is not really debatable, the one-year discrepancy comes about based on whether the accession or regnal year is being used to count from. Regardless, as to Bible prophecy and JW's 607 is only important because of their 1914 teaching. That being the case, if all that is said in connection with the 1914 teaching is false then 607 should not matter to JW's.
So, if you are an active JW and you are knowledgeable of their beliefs and if you are a honest person then answer some questions I have and see where it leads.
[9-1-15 WT – Would you like to receive truthful answers to your questions about Jehovah’s Witnesses? We encourage you to turn to the most knowledgeable source—Jehovah’s Witnesses themselves,]
[10-1-14 WT – Do you have a particular Bible subject that you have wondered about? Are you curious about any of the beliefs or religious practices of Jehovah’s Witnesses? If so, do not hesitate to ask one of Jehovah’s Witnesses. He or she will be pleased to discuss such matters with you.]
So to start with:
1. Can you tell me what is this verse describing and if it has been fulfilled yet?
[Joel 3: 2 I will also collect together all the nations and bring them down to the low plain of Je·hoshʹa·phat; and I will put myself on judgment with them there on account of my people and my inheritance Israel, whom they scattered among the nations; and they apportioned out my own land.]
2. Can you tell me if according to the Scriptures, are the trumpets blown in chronological order and if the 42-months take place during the 6th trumpet and are part of what is called the 2nd woe?
[Revelation 8:7 And the first one blew his trumpet.]
[Revelation 8:8 And the second angel blew his trumpet]
[Revelation 8:10 And the third angel blew his trumpet]
[Revelation 8:12 And the fourth angel blew his trumpet]
[Revelation 8:13 And I saw, and I heard an eagle flying in midheaven say with a loud voice: “Woe, woe, woe to those dwelling on the earth because of the rest of the trumpet blasts of the three angels who are about to blow their trumpets!”]
[Revelation 9:1 And the fifth angel blew his trumpet.]
[Revelation 9:12 The one woe is past. Look! Two more woes are coming after these things.]
[Revelation 9:13 And the sixth angel blew his trumpet.]
[Revelation 11:2 But as for the courtyard that is outside the temple sanctuary, cast it clear out and do not measure it, because it has been given to the nations, and they will trample the holy city underfoot for forty-two months.]
[Revelation 11:14 The second woe is past. Look! The third woe is coming quickly.]
[Revelation 11:15 And the seventh angel blew his trumpet.]
3. Do you/JW's believe the 1,000 year reign began in 1918 and we are 105 years into it?