Global flood chronology
The flood story has always been plagued by problems with the exact chronology. The bible often gives many conflicting statements about the duration and sequence of events. In the story of Noah's ark we get many conflicting dates for different events.
 40 days
Forty days is the duration of the flood most commonly accepted by the church. Genesis 7:17 is the least ambiguous about the flood's duration.
And the flood was forty days upon the earth; and the waters increased, and bare up the ark, and it was lift up above the earth.
Creationists will usually claim that this verse refers to how long it rained. The ";" means that the actions are being performed simultaneously though so that means that the ark did not lift after forty days but that it lifted during the forty days. This means we can consider the part before the semicolon on its own, which clearly states that it was the flood not the rain that was forty days upon the earth. This is also a translated verse. Other translations have it saying: "the waters" instead of "and the waters", which certainly sugests forty days as the flood duration.
 150 days
Then we get this quote that seems to say that the flood was 150 days in duration:
8:3 - And the waters returned from off the earth continually: and after the end of the hundred and fifty days the waters were abated.
These verses tell us that the ark landed "upon the mountains of Ararat" 5 months (150 days, assuming each month has 30 days) after the flood began, this is the same day that the "the waters were abated":
7:11 - In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened.
8:4 And the ark rested in the seventh month, on the seventeenth day of the month, upon the mountains of Ararat.
(A tradition has grown that the Ark landed on a particular mountain, which resulted in that mountain acquiring the name of Mount Ararat some time after the completion of the Bible.)
 47 days
8:6 And it came to pass at the end of forty days, that Noah opened the window of the ark which he had made:
8:9 But the dove found no rest for the sole of her foot, and she returned unto him into the ark, for the waters were on the face of the whole earth...
Then, in v8:10-11, he waited another 7 days for a total of 47 days and the dove came back with an olive leaf indicating land. Doesn't this contradict both previous accounts of 40 days and 150 days?
8:10 And he stayed yet other seven days; and again he sent forth the dove out of the ark; 8:11 And the dove came in to him in the evening; and, lo, in her mouth was an olive leaf pluckt off: so Noah knew that the waters were abated from off the earth.
 253 days
With verse 8:5 we get another contradictory date for an event in the flood.
8:5 And the waters decreased continually until the tenth month: in the tenth month, on the first day of the month, were the tops of the mountains seen.
Assuming that these dates are based of Noah's age then 153 days after the flood began the bible claims "the tops of the mountains seen". Even if the dates are not based of Noah's age we can still see that the bible claims this happened around 3 months after the ark rested upon the mountains of Ararat.
 314 days
8:13: And it came to pass in the six hundredth and first year, in the first month, the first day of the month, the waters were dried up from off the earth: and Noah removed the covering of the ark, and looked, and, behold, the face of the ground was dry.
 See also
- Bringing the animals to the ark
- Caring for the animals in Noah's ark
- Flood geology
- Global flood
- Insects during the global flood
- Noah's Ark
- Plant survival during the global flood
- Post flood animal survival
- Survival of aquatic species during the global flood