Daniel chapter nine contains one of the most remarkable prophecies jn the Bible. It was given to Daniel by the angel Gabriel. Gabriel told him:
"Seventy weeks are determined
For your people and for your holy city,
To finish the transgression,
To make an end of sins,
To make reconciliation for iniquity,
To bring in everlasting righteousness
To seal up vision and prophecy,
And to anoint the Most Holy.
"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.
"And after the sixty-two weeks
Messiah shall be cut off, but not for himself;
And the people of the prince who is to come
Shall destroy the city and the sanctuary.
The end of it shall be with a flood,
And to the end of the war desolations are determined.
"Then he shall confirm a covenant with many for one week;
But in the middle of the week
He shall bring an end to sacrifice and offering
And on the wing of abominations shall be one who makes desolate,
Even until the consummation which is determined,
Is poured out on the desolate."
The "weeks" are weeks of years - periods of seven years. So from the command to restore and rebuild Jerusalem to the coming of Messiah the Prince was to be a total of 69 weeks, or 483 years. Taking a biblical year as 360 days, that would come to 173,880 days.
In a book The Coming Prince, published in 1894, Sir Robert Anderson, Metropolitan Police assistant commissioner, theologian and author, said Ahasuerus' command to rebuild Jerusalem (Neh 2:5-8) was made on March 14, 445 BC.
Christ always refused efforts to proclaim Him king until the time came for Him to fulfil Zech 9:9:
"Rejoice greatly, O daughter of Zion!
Shout, O daughter of Jerusalem!
Behold, your king is coming to you;
He is just and having salvation,
Lowly and riding on a donkey,
A colt, the foal of a donkey."
Assuming Christ began His ministry in AD 28 (Luke 3:1) and He died at Passover, then the date of His triumphal entry into Jerusalem would be April 6, AD 32. Adding extra days for leap years, March 14, 445 BC to April 6, AD 32 is - 173,880 days.
The crowd rejoiced and praised God as Jesus approached Jerusalem, but when He saw the city, He wept. The reason? "Because you did not know the time of your visitation" (Luke 19:44). He foresaw the destruction of the city and the Temple, accompanied by the slaughter of countless thousands.
You will need to refer to Anderson's book to check the accuracy of his calculations - but the accuracy of the prophecy is remarkable
Notice that this Old Testament prophecy says that Messiah had to come before the destruction of the Temple. The Temple was destroyed in AD 70.
We have accounted for 69 of the 70 weeks. Which leaves one week still to be accounted for.