- 5 months from flood waters starting (May 17th) to flood waters subsiding and Ark grounding on Mt Ararat (Oct 17th). 
- 5 and a half months from Ark grounding on Mt Ararat (Oct 17th) to the ground being dry (Apr 1st). 
- 2 months from ground being dry (Apr 1st) to being completely dry enough to come out of the Ark (May 27th). 
Therefore, the total length of time for the flood waters to subside and for the ground to dry out was 7 and a half months.
These are very realistic figures, whereas many myths (as opposed to a true story) would not even consider facts like how long it would take for the land to completely dry out.
 Gen 7:11 and Gen 8:4
 Gen 8:4 and Gen 8:13
 Gen 8:13 and 8:14
Scroll image: thanks to GSP 100,000 Clipart CD