I can write pi accurately: π
That's the symbol that represents the value of the constant that cannot be expressed with complete accuracy with numbers.
Not to quibble...well, to quibble...I said "if."
Well, of course there are reasons for thinking that it might not be literal 24-hour periods. Just like there are reasons to believe a lot of other things in the Bible aren't literal.
I mean, nobody takes all of the Bible literally. We just sometimes disagree on where and how the lines are drawn.
Then again, sometimes things that once appeared obvious no longer do and vice versa. Most people no longer believe the world literally has "corners." But they used to.