'Days' in the Bible

Shortly after Saul had died, David returned from defeating the Amalekites and remained in Ziklag for two days.

so he sent messengers to Tekoa to bring a wise woman from there. He told her, "Please play the role of a mourner, wear the clothes of a mourner, and refrain from using makeup. Act like a woman who's been in mourning for the dead for many days.

Meanwhile, David ordered Amasa, "Muster the army of Judah here within three days, and be here yourself!"

So she said, "In days past, people used to settle a dispute by saying "Let's ask for advice at Abel!'

Then he turned them over to the custody of the Gibeonites, who hanged them on the mountain in the presence of the LORD. All seven of them died at the same time. They were executed during the first days of harvest, just as the barley began to be gathered in.

Eventually they proceeded to Beer-sheba in the Judean Negev. After they had traveled throughout the entire land, they returned to Jerusalem at the end of nine months and 20 days.

So Gad went to David and asked him, "Shall seven years of famine come to your land, or three months of reversals while you flee from your enemies as they pursue you, or three days of pestilence in your land? Decide right now what I am to answer to the one who sent me."