Not P but Moby-Dick (80)

[Mike Jing]

>From Chapter 99:

“If the White Whale be raised, it must be in a month and a day, when the
sun stands in some one of these signs.  I’ve studied signs, and know their
marks;  they were taught me two score years ago, by the old witch in
Copenhagen. Now, in what sign will the sun then be?  The horse-shoe sign;
 for there it is, right opposite the gold.  And what’s the horse-shoe
sign?  The lion is the horse-shoe sign—the roaring and devouring lion.
Ship, old ship!  my old head shakes to think of thee.”

Most of the previous translations interpreted "a month and a day" as a
length of time of exactly one month plus one day, that can't be right, can
it?

Or does it mean a certain month and a certain day, modified by "when the
sun stands in some one of these signs"?