Think this over. This info is from many places.

Here is the prediction of the Coming of the Messiah from Daniel 

“Know therefore and understand, that from the going forth of the

commandment to restore and to build Jerusalem unto THE MESSIAH

THE PRINCE shall be seven weeks, and threescore and two weeks: the street shall be built again, and the wall, even in troublous times. And after threescore and two weeks shall Messiah be cut off, but not for Himself: and the people of the prince that shall come shall destroy the city and the sanctuary” (Daniel Chap. 9 verses 25-26).

The date of the “commandment to restore and to build Jerusalem”

was the decree by Artaxerxes in 444 B.C. granting permission to the

Jews to return to Israel and rebuild the city of Jerusalem (see Nehemiah Chap. 2 verses 1-8).

The Hebrew word translated “weeks” in the Scripture quoted above

(Daniel Chap. 9 verses 25-26) means “sevens” or “heptads,” and is used for years. (See Leviticus Chap. 25 verse 8; Genesis Chap. 29 verses 27-28.) In other words, the “seventy-sevens” that are prophetically determined on Israel and on the holy city, with specified events (verse 24), is a period of 490 years. This period is divided into three sections:

(1) Seven “weeks,” or seven sevens of years-the 49 years the prophet allot-28

ted for the rebuilding of Jerusalem under the leadership of Nehemiah and Ezra and those associated with them (see the books of Nehemiah and Ezra). History tells us it took 49 years to do this rebuilding job.

(2) A second period of 62 “weeks,” or 434 years, which would bring the time to the MESSIAH.

(3) The 70th “week,” a period of seven years some

time after the coming of the Messiah.

We now are especially interested in the period “from the going forth

of the commandment to restore and to build Jerusalem” to “Messiah the

Prince,” which totals to a period of 483 years. Sir Robert Anderson, in

his book “The Coming Prince,” figured it out, and gave the world his

findings. We quote from the facts he presents:

He starts with March 14, 444 B.C., the date of the commandment to

restore and build Jerusalem; and he ends the period with Jesus’ triumphal

entry into Jerusalem (which he believes was the official presentation

of the Messiah as “Prince” to Israel. Matthew Chap. 21 verses 1-9

with Zechariah Chap. 9 verse 9). After careful investigation and consultation

with noted astronomers, he gives these startling findings: “From

444 B.C. to 32 A.D. is 476 years; 476 X 365 is 173,740 days; from

March 14 to April 6 (the day of Christ’s triumphal entry) is 24 days, add

116 days for leap years, (For a year to be a leap year, it must be exactly

divisible by four, unless the year ends in two zeros; then it must be divisible

by 400), and you get a total of 173,880 days. Since the prophetic

year of the Bible is always 360 days, the 69 ‘sevens’ of this prophecy in

Daniel (69 X 7 X 360) is 173,880 days! And so the time given by Daniel

from the ‘commandment to restore and build Jerusalem’ to ‘Messiah the Prince’ comes out perfectly-to the very day!”

LAYING OUT the TIME LINE for the 69 WEEKS

1. TRACKING the 69 WEEKS, or 173,880 DAYS,
USING the LUNAR and SOLAR CYCLES RATHER THAN
THE JULIAN/GREGORIAN (SOLAR ONLY) CALENDAR.

2. The PASSAGE of the NISAN MOONS
for 445 B.C. and for 32 A.D.

3. ASTRONOMICAL DATA on the SLOWING LUNAR ORBIT.

4. LAYING OUT the TIMELINE for the 69 WEEKS BASED on the LUNAR CYCLES.

In our investigation of the 70 weeks we saw that the first 69 weeks (or heptades, - like decades, but comprising 7 years rather than ten) was a certain number of days based on a perfect, holy solar system with annual cycles of 360 days. So the number of days for the 69 weeks was;

69 x 7 = 483 years of 360 days for each biblical year.

This ends up being
69 x 7 x 360 = 173,880 days.

This, then, is the number which Sir Robert Anderson arrived at for the 69 weeks. The next step is to lay out that number of days across a time period in history. It must start from an edict permitting the restoration of Jerusalem and run to a termination point in time auspicious as the day of "Messiah the Prince".

There are two ways to approach this. The first is using the Julian/Gregorian solar calendar such as we have it today. This is quite a reasonable way of measuring a span of time. However, we still have to connect our non-lunar solar calendar to the Hebrew months based as they are on the lunar cycles as they come through for the year in question. This was the approach used by Sir Robert Anderson. He successfully laid out the 173,880 days on a timeline from the 1st of Nisan, (March 14th), in 445 B.C to the tenth of Nisan, which he said was April 6th of 32 A.D.) This remarkably accurate work, perhaps off by no more than 1-2 days (since Nisan 10 of 32 A.D. was probably closer to April 8th), is recorded in Anderson's book, "The Coming Prince". It is a landmark piece of scholarship. It is still being published today, long after the first edition came out in 1877. His book should put to rest any historicist or preterist notions that the 70 weeks have already been completed.

The other approach, and the one used by this author, is to use the pure Astronomical data of the solar and lunar cycles to lay out the timeline of the 69 weeks. The lunar cycles can accurately peg the moons for the beginning and ending Hebrew months of Nisan in question. Then the 173,880 days for the span of years between the two points in history can be laid out alongside the lunar cycles for an exceptionally accurate timeline for the 69 weeks. This neatly by-passes all concerns about calendars, leap years and such. As far as I know this laying out of the moons for the 173,880 days of the 69 weeks has not yet been published. It is all ready and waiting to be done since the astronomical data is well known. Indeed the new moon times for the Nisan months in question, accurate right down to the minute, are sitting right there in Anderson's 19th century book on pages 102 and 124. Sir Robert had written to the Astronomer Royal at Greenwich Observatory. Using (French) Largeteau's Tables the Astronomer Royal had provided him with the exact times for the new moons for Nehemiah's month of Nisan in 445 B.C. and also the Nisan moon of the Palm Sunday/Passion/Passover week for 32 A.D.. These new moon times, for the months of Nisan in question.,
(Nisan is by definition the first full moon after the spring equinox), are as follows

For 445 B.C. (-444 A.D.) it was March 13th at 0709 hrs. or 7:09 A.M. - Jerusalem time

For 32 A.D it was March 29th at 2257 hrs. or 10:57 P.M. - Jerusalem time.

With this information we are now able to start laying out the moons for the first 69 weeks of the 70 weeks. We shall start our timeline from the Nisan moon of Artaxerxes edict before Nehemiah in 445 B.C. We shall then stretch our 173,880 days across the span of years to the number of moons the timeline will cover. Armed with this whole number of moons and carrying over the number of days remaining we can then connect these moons backward to Nisan of 445 B.C. and forward to the tenth day of the Nisan moon of Palm Sunday in 32 A.D.

Let us take our 69 weeks which is 173,880 days and consider how many moons this number of days saw back in the time of the 445 B.C. to 32 A.D. period. If we look at the lunar cycles today we can come up with a very accurate number of days. The new moon to new moon time interval nowadays is a month of 29.530587 days. But is this going to be accurate if we use it for the time period of the 69 weeks two thousand years ago? The answer is "no". And why not? Because the lunar cycles are slowing down with time. The lunar months slow down by one second every 36 years. How then can we find out what the lunar cycle length was back in the time of the 69 weeks? Well if it is slowing by one second every 36 years then the average for the 69 weeks will be the lunar cycle seen half way through the 69 weeks which is in 206 B.C. This is 2206 years ago. 2206 divided by 36 = 61.28 seconds. So the moon revolved around the earth 61.28 seconds faster back in the days of the 69 weeks compared to today. There are 60 x 60 x 24 = 86400 seconds in a day. 61.3 seconds divided by 86,400 seconds = 0.000709 So the lunar cycle seen in the midst of the 69 weeks back in 206 B.C. was 0.000709 of a day faster than the lunar cycle as measured today.

So 29.530587 minus 0.000709 days

= 29.529878 days

This then is the lunar cycle seen back in the time of the 69 weeks.

Let us now check our calculated lunar cycle for the 69 weeks. We can do this by plugging it in to the time interval given to us by Sir Robert Anderson between the new moons listed above for Nisan of 445 B.C. (March 13 at 0709 hrs.) and Nisan of 32 A.D. (March 29 at 2257 hrs.). This is 476 years, 16 days, 15 hours and 48 minutes.
This is 476 x 365.2422 days + 16.658 days = 173,871.94 days
So this 173,871.94 days, (since it spans new moon to new moon), should equal a reasonably exact number of moons.
Let us divide this number of days (173,871.94) by our calculated lunar cycle for the 69 weeks which we calculated as 29.529878 days
The answer is 5,888.0006 moons

This then is a very accurate cross check on the lunar cycles of the 69 weeks. So we are right on target. We are certain now that we are looking at 5,888 moons from the new moon of Nehemiah to the new moon of "Messiah the Prince". We can now further fine tune our lunar cycle for the 69 weeks by dividing the new moon to new moon span of 173,871.94 days by this number 5,888 which is the number moons we now know the new moon to new moon span of the 69 weeks comprises. 173,871.94 divided by 5,888 would give us an extremely accurate average lunar cycle for the 69 weeks.
This number is 29.529881 days.

Let us now take another look at the 173,871.94 days. Our 173,880 days for the 69 weeks are just 8.06 days over this new moon to new moon interval. This is just the information we need. We can now say with some surety that our Nisan date for Nehemiah's edict from Artaxerxes is 8 days earlier in the lunar cycle or Hebrew month than the Palm Sunday date which followed it 5,888 moons later. Since the Palm Sunday date was on the tenth of Nisan we can go back 8 days in the lunar cycle and say that Nehemiah probably got his edict from Artaxerxes on the 10 - 8 = 2nd day of the Nisan moon in 445 B.C. Possibly, as Sir Robert Anderson surmised, it may have occurred on the 1st of Nisan allowing for the new moon being sighted on occasions one day later. This sometimes happened due to weather and atmospheric conditions as well as the vagaries associated with the official sightings of the new moon back in those times.

Having looked at the 173,880 days from the perspective of the lunar cycles let us now turn our attention to the solar cycles. If we divide our 69 weeks of 173,880 days into 365.2422, (the number of days in a solar year), we come to
476.06766 years
= 476 years and 24.7 days.
So the entry of "Messiah the Prince" into Jerusalem on Palm Sunday of 32 A.D was
476 years and 24 or 25 days further into the calendar/solar year than the date when Nehemiah received the Edict of Artaxerxes in 445 B.C. If The Edict came in March 14 of the year 445 B.C. then Palm Sunday must have been about April 7th or 8th of 32 A.D.. This must have been a late season Passover that year. An embolismal year with an extra month of Adar inserted early in the spring before the 1st month of the year, the month of Nisan is recognised puts the Passover later down the year. Then in subsequent years it drifts back 11 days until the next embolismal year. Why 11 days? Twelve lunar months of 29.5 days is a calendar of 354 days. The solar/calendar year is 11.2422 days longer than that. As the years pass by the eventually the 13th or first month of the new year will fall short of the spring equinox. It will not qualify as the moon of Nisan. Therefore an extra month, a second month in fact, of Adar is inserted as an embolism into the calendar. Such an embolismal year occurs in the Hebrew calendar about twice every seven years. Typically, after the 12 months had passed in a given springtime the rabbis would determine whether the coming moon was going to fall short of the spring equinox as it came to its fullness. If it was not going to make the equinox as the Nisan moon then the calendar would call for the insertion of an extra month of Adar, effectively a 13th month. The month following that would be declared the Nisan month. In such a year Passover and the following feasts would be later down the year than usual.

This consideration of the embolismal year is very important in view of those 24-25 extra days carrying over the whole number of 476 years. These extra days had to be crammed into the span of time that would connect two Nisan months 476 years plus 24-25 days apart. So our investigations astronomically will lead us to the conclusion that no other nearby years, (and particularly 33 A.D.) could fit the span of 476 calendar years plus those extra 24 or 25 days. The timeline only fits in between the Nisan months of 445 B.C and 32 A.D.. No other pair of Nisans will accomodate the 69 weeks! The 173.880 days of the 69 weeks require an early Nisan month as the timeline begins and a late Nisan month as the timeline ends.

This is also further proof that 32 A.D. was the year of the crucifixion. Only a long Nisan to Nisan span will accomodate the 69 weeks. The timeline requires that the month of Nisan into which the 173,880 days terminates be a late one and in an embolismal year. Only a late Nisan month for "Messiah the Prince" would accomodate the 69 weeks which comprise 476 years and those 25 extra days. 32 A.D. was such a year!

As we can see, the 69 weeks have run out. They made a beautifully accurate fit between Hebrew calendar months/moons of Nisan 1-2 of 445 B.C. and Nisan 10 of 32 A.D. In our Gregorian calendar the span extended from March 14 of 445 B.C. and terminated 476 years and 24-25 days later on April 7th or 8th in 32 A.D. This was the crucifixion year of our Lord Jesus which is confirmed also by Luke as being 32 A.D. The timeline of the 69 weeks terminated precisely as Daniel prophesied. It came to a climactic conclusion at the first advent of Jesus as "Messiah the Prince" entered Jerusalem on Palm Sunday of 32 A.D..

This leaves one seven year period left to run.

This coming 70th week will bring us into the apocalypse.

 These last seven years will bring us into the unveiling of both the mystery of iniquity and the mystery of Godliness in Christ Jesus. -1Tim.3:16
And we shall be led into the drama and the glory of the climax of the age.
The 70th week will take us on final approach to the time of our witness before men and angels;
And thus we shall enter into our destiny.
Unspeakable wonders await us further down the pilgrim pathway and beyond the strait gate. -Mat.7:13

We shall see our Messiah's second advent.
And we shall be drawn into that vision of splendour, that glory which is only to be found in Him.

Daniel's Seventieth Week (Daniel 9:27)-- known also as the Tribulation Week-- is the present focus of prophetic interest, because it still remains to be fulfilled. However, The Ancient of Days (7:9) has wisely outlined a much broader program of Seventy Weeks-- from 445 BC to 2005 AD-- that includes Christ's Atonement on Calvary, the Church's evangelization of the world, the judgment of the world, and the establishment of the Millennial Kingdom of the LORD Jesus Christ on Earth. The following is an exposition of Daniel 9:24, and is intended to emphasize some foundational aspects of "things to come" (John 16:13). All discussion and appreciation of the "things which must shortly come to pass" (Revelation 1:1) must first grapple with this revelation by the Angel Gabriel to the prophet Daniel, the "greatly beloved" (Daniel 9:23).

When the Redeemed of the LORD arrive at their Heavenly destination, much of their rejoicing will be centered upon how wise God was in planning the events of Daniel's Seventy Weeks. The Apostle Paul epitomized this very desire to make known God's Wisdom. "8 That I should preach among the Gentiles the unsearchable riches of Christ; 9 And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, Who created all things by Jesus Christ: 10 To the intent that now unto the principalities and powers in heavenly places might be known by the Church the manifold Wisdom of God" (Ephesians 3:8-10).

Seventy Weeks: Scope of the Prophecy

A period of 70 weeks (Daniel 9:24) is the equivalent of 490 days. But, was 490 days the actual intent of the revelation given to Daniel? Among the many objectives that would be attained in the Seventy Weeks is "to bring in Everlasting Righteousness" (9:24). That points to the Advent of the Messiah. "5 Behold, the days come, saith the LORD, that I will raise unto David a righteous Branch, and a King shall reign and prosper, and shall execute judgment and justice in the earth. 6 In His days Judah shall be saved, and Israel shall dwell safely: and this is His Name whereby He shall be called, THE LORD OUR RIGHTEOUSNESS" (Jeremiah 23:5-6).

Christians already know the LORD Jesus Christ to be the Sun of Righteousness With Healing in His Wings (Malachi 4:2), because of His atoning work on the Cross after His First Advent.

 But, wasn't Daniel actually being revealed the Second Advent of the Messiah and not simply the First? "Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe" (Romans 3:22). Jews, who rejected the Messiaship of Jesus, still await the Advent of their Messiah. "For they [the Jews] being ignorant of God's righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God" (10:3).

It is entirely proper to view the Seventy Weeks (Daniel 9:24) as representative of a period greater than 490 days. "After the number of the days in which ye searched the land, even forty days, each day for a year, shall ye bear your iniquities, even forty years, and ye shall know My breach of Promise" (Numbers 14:34). This passage establishes that the LORD used the possibility of equating a day for a year, i.e., in the punishment of Israel for refusing to enter the Promised Land after the negative report from the spies. Consequently, the Seventy Weeks (Daniel 9:24) can be properly interpreted as referring to a period of 490 years, because each week of 7 days would be the equivalent of 7 years, i.e., "each day for a year" (Numbers 14:34). Therefore, 70 weeks would be the equivalent of 70 times 7 years or 490 years.

In his book The Coming Prince (1895), Sir Robert Anderson carefully outlined the position that the Seventy Weeks could be taken as: (1) 69 weeks: adding together "seven weeks, and threescore and two weeks" (Daniel 9:25), plus (2) a disconnected and final 70th week, i.e., separated from the end of the 69th Week (April 6th 32 AD) by approximately 1,966 years until the beginning of the 70th Week (1998 AD): "he [the Antichrist] shall confirm the Covenant with many for one week [the 70th week]" (9:27). Anderson determined that the "commandment to restore and to build Jerusalem" (9:25) referred to the Persian king Artaxerxes Longimanus' decree to rebuild the city of Jerusalem of March 14th 445 BC (Julian). "For the wall of the city... the king [Artaxerxes, who was the son of Ahasuerus (a.k.a. Xerxes), who, in turn, was the husband of Queen Esther] granted me [Nehemiah], according to the good hand of my God upon me" (Nehemiah 2:8). Further, Anderson determined that 69 weeks of prophetic years of 360 days (69 x 7 x 360) or 173,880 days, proceeded from March 14th 445 BC (Julian) to April 6th 32 AD (Julian)-- the very Palm Sunday of our LORD's Triumphal Entry into Jerusalem.

John Gill's Expositor (1760) commented on Daniel 9:25-- "Know therefore and understand, that from the going forth of the commandment to restore and to build Jerusalem unto the Messiah the Prince shall be seven weeks, and threescore and two weeks: the street shall be built again, and the wall, even in troublous times" (Daniel 9:25)-- in agreement with Sir Robert Anderson. Incidentally, Gill did briefly state another position on the Seventy Weeks taken from Sir Isaac Newton's Observations on Daniel. John Gill summarized Newton's position: "Sir Isaac Newton thinks the seven weeks unto Messiah, which he detaches from the sixty two, respects the second coming of Christ [e.g., 7 weeks of years from May 14,1948 to May 14,1997-- a modern application by contemporary interpreters], when he [Christ] shall come as a Prince, and destroy antichrist, and that it takes in the compass of a jubilee; but when it will begin and end he [Newton] does not pretend to say."

John Gill explains his reason for disagreeing with Newton. "Within the space of seven weeks, or forty nine years, reckoning from the twentieth of Artaxerxes; when the Jews had a grant to rebuild their city and wall, and were furnished with materials for it; and which was done in very troublesome times... Nehemiah chapters four and five for which the space of seven weeks, or forty nine years, were cut out and appointed; and that this event belongs solely to this period is clear from the Messiah's coming being appropriated to the period of the sixty two weeks; which leaves this entirely where it is fixed." In other words: (1) the "seven weeks" (Daniel 9:25) points to the period encompassing the rebuilding of Jerusalem's walls, i.e., "to restore and rebuild Jerusalem" (9:25), while (2) the "threescore and two weeks" points to "Messiah the Prince" (9:25) and His First Advent. Like Gill, John Zachary in his Threshold of Eternity (1989) agrees with Sir Robert Anderson's understanding of the Seventy Weeks. I, also, agree with Anderson, Gill, and Zachary; but, am grateful to know that Sir Isaac Newton lent his time, intellect, and name to the study of "things to come" (John 16:13).

"The COMMAND to RESTORE and BUILD JERUSALEM". -Dan.9:25

The EDICT of ARTAXERXES GIVEN TO NEHEMIAH in 445 B.C. in the
HEBREW MONTH of NISAN MARKING the BEGINNING of DANIEL'S PROPHECY. of the 70 WEEKS

In the attempts to identify the starting point of Daniel's prophecy of the 70 weeks there have been a number of edicts put forward. A favorite has been the former edict issued by Cyrus in 539 B.C. in the century before Nehemiah. This earlier edict had allowed a number of returns of the exiles of Judah. The 1st return under Sheshbazzar followed soon afterward in 538 B.C.. When Darius the Mede came to power in 522 B.C. there followed a 2nd return led by Zerubbabel in 521 B.C.. The temple was rebuilt under Zerubbabel in the years 520 - 516 B.C.. The completed 2nd temple was rededicated in 516 B.C.. This was seventy years after the destruction of the former temple of Solomon by Nebudchadnezzar in 586 B.C.. Religious restoration had been fostered by the 3rd return under Ezra in 458 B.C. Many scholars have tried to attach this return under Ezra and the years 458-457 B.C. to the start of the 70 weeks. But is this credible?

It is true that after the decree of Cyrus many exiles had returned to Jerusalem and indeed the temple had been rebuilt. But no political restoration had been permitted back in the times of these first three returns. We know this for certain because Nehemiah, writing in the following century, in 445 B.C. had said that the walls were still in ruins at that time and the gates burned with fire. -Neh.2:3 This is highly significant.

The mention of walls of Jerusalem being rebuilt in Daniel's prophecy, -Dan.9:24-25, was a critical piece of the puzzle. It meant that the edict initiating the 70 week prophecy would be the one that would allow political restoration of Jerusalem. Here is the part of Daniel's prophecy giving specific mention of the rebuilding of Jerusalem complete with walls and gates.

9:24 "Seventy weeks are determined for your people and for your holy city,.............................................. 9:25 "Know therefore and understand, that from the going forth of the command to restore and build Jerusalem until Messiah the Prince, there shall be seven weeks and sixty-two weeks; The street shall be built again, and the wall, even in troublesome times. -Dan.9:24a-25

In ancient times the gates of a city were the place of the city's rulership and sovereignty, the place where laws were enacted. Nehemiah was asking the king for permission to restore those walls and gates. This matter of political restoration of Jerusalem was more of a touchy subject than just the rebuilding of the Jewish temple and the religious restoration. Some in the Medo-Persian court might have expected the king show his wrath on this upstart cupbearer. Some would have expected him to execute Nehemiah merely for asking the question. Judah was the last remnant of the former great nation of Israel. And they were still captive in Babylon. The nerve of the man! Why should the king give Nehemiah and the captives of Judah his leave to go and restore their holy city of all things? After all, wasn't the holy city of Jerusalem the very the archtypical opposite of Babylon, the center of world humanism?

Well by the mercies of God the king did give his permission.
And perhaps kings are inclined to desire having Jerusalem as a stone in their crown. Artaxerxes issued a royal edict giving Nehemiah his authority to make this historic 4th return. He also gave Nehemiah letters of passage and provisions to rebuild Jerusalem.

In his appeal to the king, Nehemiah had given special mention of the walls of Jerusalem being still broken down and in need of restoration. His burden, as he appealed to the king, was that that gates of his beloved city Jerusalem were still lying in charred ruins. As the Passover moon came up that year the captives of Judah were still out there in Babylon. And they dreamed of home.
The shame of that loss was more than they could bear. Those gates of Jerusalem had being burned with fire by the armies of Nebuchadnezzar way back in 587 B.C..

How had this great tragedy happened to God's chosen people? They had lost their national sovereignty because they had forgotten their God. They had left His covenant. They had left the place of His blessing. The city of the former mighty kingdom of David and Solomon had fallen into disarray. They had been carried off as slaves to Babylon. Now, one and a half centuries later, and still captive in Babylon under the Medo-Persians, Nehemiah and the exiles of Judah were in a melancholy mood. They were distracted by longings and homesick for the land they had left behind. Their hearts were set on returning to restore their beloved city of Jerusalem.

The year?

It was in the 20th year of Artaxerxes in 445 B.C.
And as the equinoctial moon, the passover moon of Nisan came up in that pivotal year events were beginning to unfold. Over in the royal quarters in Babylon the king was calling for his cupbearer.
Nehemiah brought wine and set it before the king.
On that particular day he was burdened and gloomy.
That was a dangerous state for a king's cupbearer (and also somewhat of a toastmaster) to be in back in those days. A man could lose his life very quickly if he displeased the king. But the fortunes of captive Judah was turning for the better. Nehemiah had the kings favour; and his ear. God was at work.
And His holy purposes were about to unfold.

The year of the edict, Nehemiah states, was the 20th year of Artaxerxes. -Nehemiah 2:1
Artaxerxes reigned from 465 B.C. to 425 B.C. and this date is very well established in secular history.
From those dates we can establish that the year of the edict to rebuild Jerusalem was 445 B.C. Nehemiah pinpointed the time further by stating that he had set wine before the king and received the edict in the Passover month of Nisan of that year. -See Nehemiah chapter 2

So astronomically, the edict came down and the seventy weeks began early in the month of the first full moon after the spring equinox of 445 B.C.. We know that because that is how the rabbis determined the Passover month of Nisan and checked their calendar every year.
Roughly twice every seven years they would find that the coming full moon was going to fall short of the spring equinox. It would thus fail to qualify for the Nisan moon. It would be considered a thirteenth or "embolismal" month. They made this determination in the early springtime as the new moon on approach to the spring equinox was first seen.

The seventy weeks prophecy is directed at Daniel's people, the saints of God.
But significantly it was also directed at the holy city of Jerusalem.
And when the edict was delivered to Nehemiah,
the permission to restore and rebuild Jerusalem had finally come.

It was a wonderful moment!]
The edict was in Nehemiah's hand.
The ink had barely dried on the page when he proceeded with plans to lead a great party of returning Jews back to restore the city of Jerusalem
(See the details in the book of Nehemiah). This is all for now.

And so the seventy weeks were off and running.