The only game playing with dates is by those who want to lock the Flood into a certain time of their choosing so they can “scientifically” deny it and then make the Bible out to be a lie.
The further back the Flood goes in time, the less evidence there will be for it as it gets lost. By locking the time in recently at a point at which people know there’s no evidence for the Flood, it’s far easier to discredit the whole thing.
It’s also incredibly intellectually dishonest.
Besides, as I’ve been told.... lack of evidence is not evidence of lack. There’ve been many things that the Bible was criticized as being historically inaccurate about that archeological evidence has demonstrated to be true.
As far as the evidence of the Flood, it’s a matter of opinion as to whether the evidence is reliable or not. I wouldn’t expect anyone who has already decided that the Bible is not true to accept as reliable evidence that proves that it is. Anyone who so wants to deny the truth of Scripture will find some way of explaining away the most obvious evidence in the world.
The most obvious evidence in the world? For the flood?
Then point it out to us.