Do you still believe that the gap between Africa and South America formed in around 12 months?
So, technically there is no need of 12 months, if they were never connected.
Good question though
The Hebrew word for "broken up" is baga and is used in other Old Testament passages (Zechariah 14:4; Numbers 16:31) to refer to the geologic phenomena of faulting. The mechanism for retreat of the Flood waters is also associated with tectonics. Psalm 104:6,7 describes the abating of the waters which stood above the mountains; the eighth verse properly translated says, "The mountains rose up; the valleys sank down." It is interesting to note that the "mountains of Ararat" (Genesis 8:4), the resting place of the Ark after the 150th day of the Flood, are in a tectonically active region at the junction of three lithospheric plates.
Ref: J. F. Dewey, et al., Plate tectonics and the evolution of the alpine system: Geol. Soc. Amer. Bull., v. 84, 1973,
Genesis states when the Earth “grew” by naming the person during whose life the shifts occured.
Read it and get educated.