No. You are conflating the ordinary Jewish lunisolar calendar with the prophetic chronological unit used in Daniel and Revelation.
The argument for a 360-day prophetic year does not depend on claiming that the Jews conducted ordinary civil life with an uncorrected 360-day calendar. It comes from the biblical equivalence of 42 months, 1,260 days, and “time, times, and half a time.” That yields twelve 30-day months, or 360 days per prophetic year.
Accordingly, the sixty-nine weeks are calculated as:
69 × 7 × 360 = 173,880 days.
That fixed prophetic interval is then mapped onto ordinary historical chronology, including the leap years of the Julian calendar. The Julian year is therefore the civil framework used to locate the dates—not the prophetic benchmark itself.
Your proposed calculation also uses a disputed starting point. The 457 BC date is based on the decree associated with Ezra 7, whereas Sir Robert Anderson begins with Nehemiah 2 in the twentieth regnal year of Artaxerxes because that passage explicitly concerns authorization to rebuild Jerusalem and its walls.
Furthermore, 457 BC to AD 30 is approximately 486 years, not Daniel’s 483 years, and “486.5 years” is not a chronological unit supplied anywhere in Daniel 9. You have selected a beginning and ending date and then reported the elapsed solar time; you have not demonstrated that this is the interval specified by the prophecy.
Anderson’s precise 445 BC–AD 32 reconstruction is very tight indeed, and yes, later scholars such as Harold Hoehner revised some of its dates. But Jewish leap months do not refute the 360-day prophetic-year argument, and a 457 BC starting point cannot simply be assumed without first proving that Ezra 7—not Nehemiah 2—is the decree intended by Daniel 9:25.
