Genesis 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.

1. About ten and a half months after the flood began - that is, on the first day of the new year, the earth was dry again.
2. The ark apparently had a cover, not just a window, that could be removed. Whether or not it could have been reinstalled once removed is another, unanswered question.