Morning to evening.
Judges 20:26, "Then all the children of Israel, and all the people, went up, and came unto the house of God, and wept, and sat there before the LORD, and fasted that day until even, and offered burnt offerings and peace offerings before the LORD."
2 Samuel 1:12, "And they mourned, and wept, and fasted until even, for Saul, and for Jonathan his son, and for the people of the LORD, and for the house of Israel; because they were fallen by the sword."
All night (awake)
2 Samuel 12:16, "David therefore besought God for the child; and David fasted, and went in, and lay all night upon the earth."
1 Samuel 7:6, "And they gathered together to Mizpeh, and drew water, and poured it out before the LORD, and fasted on that day, and said there, We have sinned against the LORD. And Samuel judged the children of Israel in Mizpeh."
Nehemiah 1:4, "And it came to pass, when I heard these words, that I sat down and wept, and mourned certain days, and fasted, and prayed before the God of heaven,"
Esther 4:16, "Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise; and so will I go in unto the king, which is not according to the law: and if I perish, I perish."
1 Samuel 31:13, "And they took their bones, and buried them under a tree at Jabesh, and fasted seven days."
1 Chronicles 10:12, "They arose, all the valiant men, and took away the body of Saul, and the bodies of his sons, and brought them to Jabesh, and buried their bones under the oak in Jabesh, and fasted seven days."
Our Lord fasted forty days
Matthew 4:2, "And when he had fasted forty days and forty nights, he was afterward an hungred."
While fasting we must also deny the fleshly desires to do wrong. Some fast, but never do so in the right spirit.
Isaiah 58:6, "Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?"
The "Daniel fast" (as I call it) would be similar to bread and water.
Daniel 10:3, "I ate no pleasant bread, neither came flesh nor wine in my mouth, neither did I anoint myself at all, till three whole weeks were fulfilled."