'Weeks' in the Bible

"Seventy weeks have been determined concerning your people and your holy city to put an end to rebellion, to bring sin to completion, to atone for iniquity, to bring in perpetual righteousness, to seal up the prophetic vision, and to anoint a most holy place.

So know and understand: From the issuing of the command to restore and rebuild Jerusalem until an anointed one, a prince arrives, there will be a period of seven weeks and sixty-two weeks. It will again be built, with plaza and moat, but in distressful times.

Now after the sixty-two weeks, an anointed one will be cut off and have nothing. As for the city and the sanctuary, the people of the coming prince will destroy them. But his end will come speedily like a flood. Until the end of the war that has been decreed there will be destruction.

In those days I, Daniel, was mourning for three whole weeks.

I ate no choice food; no meat or wine came to my lips, nor did I anoint myself with oil until the end of those three weeks.