It is my belief that any Christian who claims that the Earth is only 6,000 years old is applying incorrect translation and interpretation to the Biblical text - because I don't see that when I read it.
I obviously don't get an exact number - but there is nothing that suggests that the Earth is that young.
Yes, even in Scripture the word 'day ' has shades of meaning '.
For example: Jesus spoke of Noah's day and we know that was Not a 24-hour day.
ALL of the 'creative days' are summed up by the word ' day ' at Genesis 2:4.
There is Nothing in Scripture that even says whether each creative day was of the same or of differing lengths of time.
Some science because of the accuracy of microwaves CMBR ( cosmic microwave background radiation ) date the earth and universe as billions of years which is Not out of harmony with Genesis.
So, then it seems that it is only the fake 'weed/tares' Christians that believe Earth is only 6,000 years old.