For the Jews, the new day begins - or used to begin - at sundown - and the practice was widespread. We keep it in some instances today. It's why we have "Christmas EVE" and "Hallow E'EN". The Eve is the beginning of day. So... Friday after sundown, in the Olden Ways, is Saturday.
Also, someone pointed out that Latin alphabet had no "J", so that Jehovah was written with an "I". There's more to that: Latin also had no "V" as we use it today for the voiced "F" sound, and the letter "V" apparently was more of a "U" or "W" sound as we use them today. Phonetically, it seems that the name likely sounded like YahWay.
Here's where it gets interesting. The Romans were supposedly quite tolerant of various religious beliefs, but they had their own chief God, whom they called Jove, same as the name of the planet Jupiter, or Zeus Pater. But - here you go again. No "J" and no "V-sound", so Jove is actually written as IOUE, and likely pronounced YohWay... which I'd say is pretty damn close to YahWay.
Your mileage may vary.
Go hunt for the egg-laying rabbits, now. The best part is they lay hard-boiled eggs. Well, and chocolate ones, too.