Problem No. 1 - Not 69 weeks exactly
Perhaps the most fun and easiest thing anyone (except Anne, sorry!) can do is go into onlineconversion.com/julian_date.htm and enter in the dates and see if they add up to 483 years, to the exact day. This website gives the Julian Number for each date.
For Robert Anderson's dates:
Enter 6th April CE 32. [Answer = 1732842] (Use 12hr, 0 min, 0 sec)
Enter 14th Mar BCE 445. [Answer = 1558959]
1732842 - 1558959 = 173883 (days).
173883 / 360 does not give an integer answer. It is actually 173880 / 360 which gives an integer answer. Therefore Anderson's date range is not 69 weeks ( 483 years ) to the exact day!
Now let us look at Hoehner's dates:
Enter 30th March CE 33. [Answer = 1733200]
Enter 5th March BCE 444. [Answer = 1559316]
1733200 - 1559316 = 173884 days.
173884 / 360 does not produce an integer value. It is 4 days longer than 483 years (or 69 weeks).
Therefore Hoehner's date range is not 483 years, 69 weeks, to the exact day either.
(Actually, to be fair, it would have been better not to include the first day of each date range: this would have meant Anderson was 2 days in error, and Hoehner was 3 days in error. The difference between 10th Jan 2021 and 10th Jan 2022 is 366 days: if we want to know how much 10th Jan 2022 is beyond 10th Jan 2021 we need to start with 11 Jan 2021 and end with 10th Jan 2022.)
Now just for fun let us take another date range. This is from 1st Nisan 458 BCE (obedience to the decree of Artaxerxes to restore Jerusalem to Jewish rule and rebuild it in Ezra 7:9) to the Resurrection Day on 5th April CE 33 (Julian), assuming the crucifixion was on 3rd April 33 CE (Julian).
1st Nisan 458 BCE was 8th April 458 BCE (Julian).
Enter 5th April 33 CE. [Answer = 1733206]
Enter 8th April 458 BCE. [Answer = 1554236]
1733206 - 1554236 = 178970.
178970 / 365.24219 (solar year) = 490.00363 (or 70 weeks and 1 day). Starting with 9th April 458 BCE as explained above gives 490 solar years (70 weeks) to the exact day.
When Hoehner changed the 20th year of Artaxerxes from 445 BC to 444 BC he also, unfortunately, changed all of Artaxerxes's other years so that his 7th year (Ezra chapter 7) became 457 BC and not 458 BC. In this part of his theory Anderson was at least correct.
Problem No. 2 - there was no decree given in either 445 or 444 BC
445 BC is the year Nehemiah returned to Jerusalem in Nehemiah chapter 2 because Artaxerxes gave him permission. But the Bible does not mention any decree at this time. The last decree given was in 458 BC in Ezra 7:13.
Problem No. 3 - Hoehner's 5th March 444 BC could not possibly have been 1st Nisan.
5th March (Julian) is 28th February 444 BC Gregorian. This would have meant Passover falling on 13th March (Gregorian). This is completely impossible because Passover always had to fall after the Spring Equinox on (Gregorian) 21st March! So Hoehner's start date is wrong by a month. 1st Nisan in 444 BC came after the New Moon and was no earlier than 3rd April (Julian). So once again the date range is nothing like 69 weeks to the exact day.
For a more detailed critique see
https://www.oxfordbiblechurch.co.uk/index.php/books/new-book-daniel-s-70-weeks/475-appendix-2-anderson-hoehner-interpretation-a-critique
This is a critique by a Pastor who is himself a dispensationalist.
Another website from the dispensationalist fold which demolishes both Anderson and Hoehner can be found here: https://www.pickle-publishing.com/papers/harold-hoehner-70-weeks.htm (Thanks to Lesley for finding this.)
It seems modern dispensationalists are very aware of the shortcomings of the theories of both of these men.
It is, I think, very regrettable that some Christians, who otherwise show signs of being non-dispensationalists, are not aware of these problems and continue to quote the theories of these two men as authoritative and with approval.