The Lunar Theory.
I'm sure this has been noted several times before, but I couldn't seem to find the official thread for it, how long I actually looked for it. If such as an official thread for this exist, please post it.
Anyhow, if we assume that the moon's phases works in the same manor in Odaverse as in the Universe, then we can more or less accuratly count the time that has passed since the Straw Hats left Syrup Village.
Which gives us that it's gone 40-50 days since the Straw Hats left Usopp's village. This means that a cople of until recently unknown nobodies has in less then two months created a pirate crew with a bounty on over 600 million bellies, destroyed Enies Lobby, defeated a Shichi Bukai and manage to get a Buster Call on them.
It's also pretty interesting to think of that the mean time in Odaverse in comparison to ours is that during those 10 years we've been reading One Piece, less than two months have passed.
Anyway, the point of this is that this could possibly make it possible for us to calculate the time it would take for the Straw Hats to get to Raftel. Well, as they entered the Grand Line on day 10, and the size of OP-Earth seems to be the same as real life-Earth, then how long could it take?
If we judge that they've been travelling for 30-40 days in the Grand Line by now, then how long to make a full travell around the world?
Who hasn't read Jules Vernes classic Around the World in 80 days? Could this perhaps be a clue? Oda claimed that OP was about half finished by now, and wouldn't it then seem probable that with the technology of One Piece be so that about 80-90 days would be the time to be estimated for travelling around the world?
Of course, that theory is based on pure assumptions, guesses and wishes, but I still think that that theory should be taken into consideration.