From one New Moon to another and from one Sabbath to another, all mankind will come and bow down before me," says the LORD. -- Isaiah 66:23 (New International Version)
24 Hours, 37 Minutes is the length of the Martian day. 687 Earth Days is the length of the Martian year.
The Sabbath is kept from sundown to sundown. It follows that this method of observing God's special day (creation & deliverance from slavery or sin) would be based on the setting of the sun on Mars after 24 hrs and 37 min. If you add up the extra 37 minutes, at some point the Sabbath day on Earth will have passed in relation to the one kept on Mars. For the Martian colonists, Adventist or Jewish, the Sabbath day would be as meaningful even if it lasts 37 minutes more than it does on Earth. Given enough time though, the weekly seventh-day cycle would be so out of sync with the actual 24-hour Sabbath and seven-day week on Earth, that the Martian colonists would, in effect, be keeping something appropriate to the time and place in which they find themselves, however far removed from the actual 24 hour day and seven day week as it exits on Earth. As more and more weeks, months and years pass by, the two Sabbath "days" would be farther and farther apart in time though not in intent.
What does this mean for us who are not yet on Mars, though our descendants may well live there some day?
As a child most of the Adventists I knew kept sundown calendars so they could begin and end the Sabbath exactly when the sun set on Friday and Saturday. Sometimes it was perplexing when we couldn't find the calendar and had to keep on looking at the sky to see if it was dark enough yet. It sounds vaguely legalistic to me. It didn't bother me that much at the time.
Yesterday, it rained all day. I showered late and never got to do much of anything on my day off. I have not used the calendar method of beginning or ending the sabbath for eons now. My dilemma was there was a lovely piece of secular music I wanted to hear all day. The sky looked vaguely pre-sunset though it was hard to tell as the rain and overcast quality of the sky had made it dark all day. I took my chance with a tinge of Sabbath preparatory anxiety. I enjoyed my 3 minute secular song on cd, "The Day that it rained forever" by Nick Heyward. I then remembered who I was sitting with when last I heard that song. I enjoyed the coziness of the music and the swirling string arrangements as well as the power of simple song craft to renew one's inner vision. The song ended and I waited for the Bible to open itself to the accidental, or perhaps not so accidental text, something in Ezequiel about how "The End had come." It was interesting but a bit too severe for a vesper text so I tried my usual Sabbath author Isaiah. Anything near chapter 53 is usually appropriate for me.
The ethereal music I had experienced during the pre-Sabbath day, the insularity of the rain-flecked "green architecture" windows, and the momentary shock of Ezekiel's "End of the World" prophecy brought to mind my past meditations on the Sabbath day and how to find meaning and sustenance in an enhanced version of the Sabbath. I thought of future Adventists or Jewish believers who would have the financial ability and, perhaps, vision to escape Earth's violence, global warming and overcrowding to settle on Mars 100 years from now.
I was then reminded again of my unusual attempts to enhance the Sabbath by extending the hours of reflection & meditation till the sun rose on Sunday morning. A month ago when walking the dog at midnight on a Saturday night, or early Sunday morning, I briefly meditated on the enhanced Sabbath day it is my habit to observe since the spring of this year. Yes, it's not biblical, but some would say the same thing about the Investigative Judgment or, at least, the "pre-advent judgment," depending on whether you are a traditional modern Adventist or a post-modern or "progressive" believer. Once or twice I felt a bit of guilt for wanting to extend the Sabbath meditation beyond Sunset on Saturday night. Guilt is a two-edged sword. It can cut away the wrong things we do, but it can also limit the creative and new things or new ways to think about things that are normally possible.
In the end the important thing is the spiritual blessing you derive from the Sabbath. It may be the traditional sunset to sunset 24-hour Sabbath. It may be an enhanced conceptual sabbath. Or it may be, someday, a 24 Hrs, 37 Mins Sabbath day on the Martian colonies in the 22nd century.