On this calendar the Sabbath is line up with the seventh day of the month of Nisan. It is not lined up with the seventh day of the week based on the Gregorian calendar because when it was established there was no Saturday, or week as we know it now. There was only the sun, moon and stars for signs and seasons. The new moon always was a sign of the beginning of the month. In the Garden of Eden days were by number not name. In the wilderness of Sinai, the children of Israel had no calendar. The Lord delivered them out of the times of Egypt. All they had was Him to establish their time, and His time is not Egyptian time, Babylonian time, Roman time, Gregorian time, or any other time. The Lords time is completely set apart to Him and only He can establish it. Through many years in the Diaspora and mixing with other cultures things began to change. In Genesis, the Sabbath was originally the seventh day of the beginning. In Exodus 12:2 the Lord then established the month of Nisan as the new beginning, and the seventh day of the beginning (Nisan) starts the Sabbath once again. This means that the Sabbath moves from year to year, just like His people. All other Sabbaths (Feasts Days) change from year to year and the seventh day Sabbath does the same, but it always starts with the seventh day of the beginning. When the children of Israel were taken captive by other cultures the Sabbath was always one thing that made them stand out; it became a source of persecution for them. Our desire here is not to confuse, but to get back to the basic things of God.