'Days' in the Bible

Now it came to pass after the death of Saul, when David was returned from the slaughter of the Amalekites, and David had abode two days in Ziklag;

And when thy days be fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, which shall proceed out of thy bowels, and I will establish his kingdom.

And the counsel of Ahithophel, which he counselled in those days, was as if a man had inquired at the oracle of God: so was all the counsel of Ahithophel both with David and with Absalom.

Then said the king to Amasa, Assemble me the men of Judah within three days, and be thou here present.

Then there was a famine in the days of David three years, year after year; and David inquired of the LORD. And the LORD answered, It is for Saul, and for his bloody house, because he slew the Gibeonites.

And he delivered them into the hands of the Gibeonites, and they hanged them in the hill before the LORD: and they fell all seven together, and were put to death in the days of harvest, in the first days, in the beginning of barley harvest.

So when they had gone through all the land, they came to Jerusalem at the end of nine months and twenty days.

So Gad came to David, and told him, and said unto him, Shall seven years of famine come unto thee in thy land? or wilt thou flee three months before thine enemies, while they pursue thee? or that there be three days' pestilence in thy land? now advise, and see what answer I shall return to him that sent me.