'Weeks' in the Bible

“Seventy weeks [of years, or 490 years] have been decreed for your people and for your holy city (Jerusalem), to finish the transgression, to make an end of sins, to make atonement (reconciliation) for wickedness, to bring in everlasting righteousness (right-standing with God), to seal up vision and prophecy and prophet, and to anoint the Most Holy Place.

So you are to know and understand that from the issuance of the command to restore and rebuild Jerusalem until [the coming of] the Messiah (the Anointed One), the Prince, there will be seven weeks [of years] and sixty-two weeks [of years]; it will be built again, with [a city] plaza and moat, even in times of trouble.

Then after the sixty-two weeks [of years] the Anointed One will be cut off [and denied His Messianic kingdom] and have nothing [and no one to defend Him], and the people of the [other] prince who is to come will destroy the city and the sanctuary. Its end will come with a flood; even to the end there will be war; desolations are determined.

In those days I, Daniel, had been mourning for three entire weeks.

I ate no tasty food, nor did any meat or wine enter my mouth; and I did not anoint (refresh, groom) myself at all for the full three weeks.