I have friends who are Seventh Day Adventists,who state that the Sabbath is always on a Saturday and it's right there in the Bible.And the Sunday worship is of the Devil.Then I found this...A claim that the true Sabbath found in the Hebrew scriptures/texts/Bible
by theworldslastchance @ http://www.theworldslastchance.com a supposed breakaway from the common Seventh Day Adventist movement,that the ancient Hebrews used a creator's calendar,followed a Lunar-Solar cycle in the bible in the book of Genesis 1:4,had a 29-30 day month, relied on a crescent moon,used a new or full moon to determine the start of a new month,preparation days prior to Sabbaths on the 8th,15th,22nd,29th of every month.And refute the Gregorian and Julian calendar as a Pagan calendar, but deem it okay its use to determine the Sabbaths.They have a breakaway from them,who argue they have their dates for the Sabbath all wrong.
The Saturday Swindle: Hiding the Sabbath - Part 1