Tell your dub friend he/she is all wet. We don't even need any secular proof to show 607 is NOT the date of the destruction of Jersulam.
Your friend uses 539 BC as an anchor date. Fine, let's use that date:
539 BC - Babylon fell to during the rule of Nabonidus. Nabonidus ruled 17 years.
539 + 17 = 556 BC. Start of Nabondus reign, end of Labishi-Murduk reign. Labishi-Murduk reigned 9 months, or say 1 year.
556 +1 = 557 BC. Beginning of Labishi-Murduk reign, end of Neriglissar reign. Neriglissar reigned 4 years.
557 + 4 = 601 BC. Beginning of Neriglissar reign, end of Evil-Merodah reign. Evil Merodach reigned 2 years.
601 + 2 = 603 BC. Beginning of Evil Merodach reign, end of Nebuchadnezzar reign. Nebuchadnezzar reigned 43 years and Jersusalem was destroyed in the 19th year of Nebuchadnezzar's reign.
43 years of reign for Nebuchadnezzar - 19th year of his reign when Jerusalem was destroyed = 24 years of reign AFTER Jerusalem destroyed.
603 - 24 years of reign AFTER Jerusalem was destroyed = 587 BC. When Jerusalem was destroyed.
Sources: the Bible, Aid to Bible Understanding in Insight on the Scriptures.
This is so simple and solidly documented in scripture and WTS references, even a dumb dubbie should be able to understand it. Nah!
Full explanation and sources:
http://www.jehovahs-witness.com/12/74549/1.ashx
Farkel