Missler is absolutely a giant. Here he is following a late view of the eclipse in Josephus championed first by Florian Reiss in 1880, which remains the minority report today. I grant that he is relying on Tertullian, who seems to have fallen for the same error as William Filmer in reading Luke's "about thirty" as "exactly thirty" (thus Tertullian takes 15 years after Tiberius and assumes exactly 15 years before Tiberius, arriving at 2 BC and informing his other calculations). But Hippolytus at the same time had heard of the 2 BC date, reports it, and then corrects himself by other data and backdates the birth of Christ back to 4 BC. So I think Hippolytus had it right in the end, as he had a direct apostolic chain of testimony from Irenaeus, Polycarp, and John and Mary.