Snakeway is 10,000,000 miles long. Princess Snake's Palace is at the 5,000,000 mark. In order to figure out how many days it will take you to travel, take 10,000,000 (or 5,000,000. It depends on where you are traveling to/from.) and divide it by your Speed.
10,000,000/Speed=Travel Time in days
However, there will always be a requirement of one day. Starting on the second day, for every day traveled you will earn 7500 PL points. All of this is null and void if you choose to use a teleportation technique.