Noah, animals were not on the ark for one year....a total of three and a half years. (However long a year was) it's stated in Hebrew poetic language similar to other passages but essentially "a time, two times, and half a time." But in a completely difficult fashion. (Ancient Hebrew....go figure eh)
From Scripture we are told when the flood ended, and Noah and all of the animals then came out of the Ark: -
Genesis 8:13-19: - 13 And it came to pass in the six hundred and first year, in the first month, the first day of the month, that the waters were dried up from the earth; and Noah removed the covering of the ark and looked, and indeed the surface of the ground was dry. 14 And in the second month, on the twenty-seventh day of the month, the earth was dried.
15 Then God spoke to Noah, saying, 16 "Go out of the ark, you and your wife, and your sons and your sons' wives with you. 17 Bring out with you every living thing of all flesh that is with you: birds and cattle and every creeping thing that creeps on the earth, so that they may abound on the earth, and be fruitful and multiply on the earth." 18 So Noah went out, and his sons and his wife and his sons' wives with him. 19 Every animal, every creeping thing, every bird, and whatever creeps on the earth, according to their families, went out of the ark.
NKJV
From scripture we are also told when the Flood began in the following scripture: -
Genesis 7:10-12: - 10 And it came to pass after seven days that the waters of the flood were on the earth. 11 In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened. 12 And the rain was on the earth forty days and forty nights.
NKJV
So from scripture we can calculate the duration of the Flood: -
The year month and day of the month that the flood ended: -
In the Year 601, of Noah’s life, in the second month and on 27th day of that month
The year month and day of the month that the flood started: -
In the Year 600, of Noah’s life, in the second month and on 17th day of that month
Subtracting the year, month and day of the month that the flood started from the year month and day of the month that the flood ended we can see that
the actual length of the flood was one year and ten days long.
How people can arrive at a different duration for the flood is beyond my ability to comprehend.